15 Major Projects That The Federal Government Officially Approved And Then Just Never Built

A half-finished nuclear waste tomb in the Nevada desert. A 250-foot triumphal arch nobody asked for. An 87-kilometer particle collider tunneled and then abandoned in a Texas cow pasture. The America that almost was, ranked. Here in May of 2026, the country is debating a 250-foot triumphal arch that President Trump wants built in time for the July 4 sestercentennial. The legal justification the administration is using is, of all things, a 1924 federal report that authorized a similar (much smaller) ceremonial structure on the same site, which was never built. Per the Washington Post, Trump officials are arguing they don't need new congressional approval because, technically, the project was already approved a century ago.

That got me thinking. How many other American landmarks, monuments, scientific facilities, and infrastructure megaprojects were officially approved at the federal level, then for one reason or another just never happened?

The answer turns out to be a lot. The graveyard of American ambition is enormous. So we got the team together and pulled what we think are the 15 most consequential, interesting, or genuinely strange federally-approved projects that never made it into the physical world. Some were monuments. Some were dams. Some were giant scientific experiments. One involved using 520 hydrogen bombs to dig a canal across Israel.

This is the America that almost was.

How are we defining "approved" and "never built"?

For inclusion, a project had to clear a meaningful federal hurdle. That usually means an act of Congress, a signed bill, a federal appropriation, formal approval by a federal commission, or at minimum a presidential authorization. We tried to focus on projects with genuine governmental traction, not back-of-napkin sketches.

"Never built" means the project as approved was never completed. Some were canceled after partial construction (the Superconducting Super Collider, Auburn Dam, Yucca Mountain). Some never broke ground at all (Mother's Memorial, the pyramid Lincoln Memorial). And in one truly bizarre case, the project was officially scrapped specifically because the federal government decided that detonating thousands of nuclear bombs to dig canals was, on reflection, a bad idea.

A spending chart, before we dive in

Most of these projects never burned much taxpayer money because they died in the design phase. But the 20th-century science and infrastructure proposals collectively burned through tens of billions before being abandoned. Here are the heaviest hitters, in inflation-adjusted dollars:

A note on the rankings

We ordered the list roughly by dollar magnitude and historical significance, not strict descending cost. So Yucca Mountain leads at #1 (most expensive failure by far), but the Trump arch's 1924 antecedent shows up at #14 because that's the project everyone is suddenly talking about in May 2026 - it's the news peg for this whole article. Now let's get into it.

1Yucca Mountain Nuclear Waste Repository

Yucca Mountain is the most expensive thing the United States government ever started building and then walked away from. The Government Accountability Office estimated in 2013 that approximately $15 billion in research expenditure had been spent on the project since 1983. The Department of Energy's 2008 estimate said it would have taken up to $96 billion more to finish.

The project was first identified in 1987 when Congress passed the Nuclear Waste Policy Act Amendments and designated Yucca Mountain as the country's sole site for the disposal of high-level nuclear waste. In 2002 Congress and President Bush formally approved development with Public Law 107-200. The plan was to bury 70,000 metric tons of spent nuclear fuel and high-level radioactive waste in tunnels 1,000 feet below the Nevada desert. About 1,000 feet above the water table. About 100 miles northwest of Las Vegas.

Nevada hated it. Senate Majority Leader Harry Reid (D-Nev) made killing Yucca Mountain his life's political work. The Obama administration pulled federal funding in 2011 and effectively terminated the project. As of 2026, the tunnels sit empty. Not one ounce of nuclear waste was ever stored there.

The full cost remains contested. The Government Accountability Office cited approximately $15 billion in research expenditure as of 2013, of which $9.5 billion came directly from ratepayer electric bills via the Nuclear Waste Fund. Senator Catherine Cortez Masto repeated the $15 billion figure as recently as 2018. The Department of Energy's own 2008 estimate said the full project would have required up to $96 billion to complete the 150-year lifecycle, including operation through 2133. The Trump administration tried to revive the project in 2017 but later abandoned the effort during the 2020 campaign.

What does America have to show for that $15 billion? A 5-mile exploratory tunnel and a very long-running political fight.

2The Superconducting Super Collider

Just outside Waxahachie, Texas, 30 miles south of Dallas, there are 14 miles of empty tunnel buried in the ground. They were supposed to be part of an 87-kilometer (54-mile) ring that would have been three times the size of CERN's Large Hadron Collider. The Superconducting Super Collider would have, almost certainly, discovered the Higgs boson roughly a decade before CERN did in 2012.

Instead, on October 19, 1993, the House of Representatives voted to kill the project after $2 billion of federal money (and another $400 million from Texas) had already been spent. The Senate failed to restore funding. Congress directed the Department of Energy to begin an orderly termination.

The collapse came down to a perfect storm: continuing cost overruns (the projected total had jumped from $4.4B to $8.25B to potentially $11B+), a failure to attract international partners (only India came through, with a $50M pledge), the end of the Cold War removing some of the strategic urgency, and a new fiscal-austerity moment in Washington that came right at the wrong time. By the end the project had been over budget and behind schedule for years, with the GAO repeatedly flagging management failures.

The Texas General Land Office eventually sold the half-finished facility for $14.7 million. The buyer used the central laboratory building as a chemical storage facility. The 14-mile tunnel is still there. It's privately owned now. Sometimes people get tours.

3The North American Water and Power Alliance (NAWAPA)

You probably haven't heard of this one. You should have. NAWAPA was a 1960s proposal to plumb the entire North American continent. Designed by the Ralph M. Parsons Corporation in 1964 and developed in collaboration with the US Army Corps of Engineers, NAWAPA would have diverted approximately 15% of the freshwater runoff from rivers in Alaska and northern Canada and piped it south through Canada via the Rocky Mountain Trench, into the western and southwestern United States, all the way down to Mexico.

The scale was lunatic. NAWAPA would have required:

• 369 individual dams, canals, pipelines, tunnels, and pumping stations
• Moving 32 billion cubic yards of earth and 30 million tons of steel
• A single dam 1,700 feet tall (more than twice the height of Hoover Dam, and taller than any dam currently in the world)
• Delivery of 158 million acre-feet of water per year to the US, Canada, and Mexico
• An estimated 30-year construction timeline
• A total estimated buildout cost of $100-200 billion in 1964 dollars, which is roughly $760 billion to $1.5 trillion in 2024 dollars

In the mid-1960s, this was treated as a serious national proposition. Senator Frank Moss of Utah championed it. Congressman Harold Johnson of California advocated for it. Several congressional hearings reviewed it favorably. As historian Marc Reisner observed, the project had two minor drawbacks: it would have destroyed anything still resembling nature in western North America, and it might have required taking Canada by force.

4Project Plowshare

This one is worth knowing about because it was real, it was funded, and it was officially named after a Bible verse about "beating swords into plowshares." Project Plowshare was the US government's twenty-year program to develop nuclear bombs as civilian construction tools.

Yes. You read that correctly. The federal government, funded by Congressional appropriation, conducted 27 nuclear tests with 35 warheads over two decades to determine whether atomic weapons could be used to:

• Excavate a new sea-level canal across Central America (proposed as "Pan-Atomic Canal")
• Widen the existing Panama Canal
• Dig a deep-water harbor at Cape Thompson, Alaska (Project Chariot)
• Carve Interstate 40 through the Bristol Mountains in California (Project Carryall, using 22 nuclear blasts)
• Excavate a canal across Israel's Negev Desert as a Suez alternative (520 two-megaton nuclear explosions, estimated cost $5 billion in 2021 dollars)
• Stimulate natural gas flow in underground reservoirs (an early form of fracking, with nuclear bombs)

On 22 September 1964, Congress authorized $17.5 million for the Atlantic-Pacific Interoceanic Canal Study specifically to evaluate construction methods including nuclear excavation. The largest test ever conducted was the 1962 Sedan event in Nevada, which created a crater 320 feet deep and 1,280 feet wide. It also exposed an estimated 13 million Americans to radioactive fallout.

Plowshare officially ended in 1977 after two decades of growing public concern, mounting evidence of radioactive contamination, and an emerging understanding that nuclear excavation was not the cheap construction solution its boosters had promised. Total program cost is estimated at roughly $770 million in 2024 dollars, though the full operational figures have never been precisely disclosed.

No canal was ever dug. No harbor was ever created. The Soviets, incidentally, ran a parallel program called "Nuclear Explosions for the National Economy" with 124 detonations. They also gave up.

5Auburn Dam

Authorized by Congress in 1965 as part of the federal Central Valley Project, the Auburn Dam was supposed to rise 685 feet above the North Fork of the American River in California, creating a reservoir of 2.3 million acre-feet for water supply, hydropower, flood control, and recreation. Construction started in 1968. By 1975, taxpayers had already spent about $137 million on it.

Then in 1976, a magnitude 5.7 earthquake hit the Oroville area, about 30 miles from the dam site. The Bureau of Reclamation suspended construction to study seismic concerns. Engineering studies confirmed the original double-curvature arch dam design could not safely survive a major earthquake at the site. Multiple redesigns were proposed through the 1980s. Costs kept climbing. Environmental concerns multiplied.

On September 23, 1992, the House of Representatives voted 273-140 to block all funding. The State Water Resources Control Board revoked the Bureau of Reclamation's water rights for the project in 2008. As of 2026 the dam is still officially a congressionally authorized project. It just doesn't have any money or water rights or political will behind it.

Total federal expenditure on Auburn Dam: approximately $315 million in nominal dollars per the US Bureau of Reclamation's 2007 report, or roughly $480 million in 2024 dollars. (Wikipedia cites a higher construction-cost figure of $431 million, but the USBR report is more authoritative.) The hole is still there.

6Project Iceworm (Greenland Subsurface Missile City)

The Cold War produced many strange ideas. Project Iceworm was the strangest. The US Army planned to build, under the Greenland ice sheet, an underground nuclear missile city. The plan called for 52,000 square miles of tunnels carved into the Greenland ice (three times the size of Denmark), housing 600 Minuteman ballistic missiles mounted on rail lines so they could be moved around to evade Soviet detection, plus 60 launch control centers, all aimed at Moscow.

Approximately 11,000 American soldiers would have lived full-time beneath the ice. The project was concealed from Denmark, which actually owned Greenland at the time. The cover story given to the Danish government was that the US was building a scientific research base called Camp Century to "test Arctic construction methods."

Camp Century was built between 1959 and 1960 as the proof-of-concept. It had a chapel, a theater, a shop, and a tiny portable nuclear reactor (the PM-2A) that ran for 33 months before being decommissioned. The US Army built about 2 miles of tunnels and discovered something that probably should have been obvious from the start: the Greenland ice sheet moves. The tunnels began deforming almost immediately, with ice walls bowing inward and threatening to collapse.

The Iceworm budget was never publicly itemized. Camp Century alone reportedly cost about $7.92 million in construction plus $5.7 million for the portable nuclear reactor. In today's dollars that's roughly $80 million, but that figure only covers the prototype facility, not the broader Iceworm program (which was canceled before significant additional spending). The full intended buildout would have cost many billions had it proceeded.

7The Pyramid Lincoln Memorial

Imagine, instead of the gleaming Greek temple at the western end of the National Mall, an 8-tiered white marble ziggurat rising 250 feet into the sky, with a statue of Abraham Lincoln on top.

That was the Lincoln Memorial that architect John Russell Pope proposed in 1912. Congress had approved $2 million in 1911 (the largest national memorial budget ever appropriated at the time) and created the Lincoln Memorial Commission, headed by President William Howard Taft, to choose a design and location.

Pope, who would later design the Jefferson Memorial, the National Gallery of Art, and the National Archives, submitted multiple proposals. The most famous was a ziggurat-style pyramid styled after the temple towers of ancient Mesopotamia (the "cradle of democracy"). Pope also submitted a four-sided Egyptian-style pyramid alternative with portico entrances on each side.

The Commission of Fine Arts advised the Lincoln Memorial Commission to instead select Henry Bacon's neoclassical Greek temple design. Bacon won. Pope's pyramid stayed on paper. Bacon's temple was dedicated in May 1922 and remains one of the most recognized buildings in America.

8National American Indian Memorial

One of the most ambitious unbuilt American monuments was the National American Indian Memorial, a project funded by department-store magnate Rodman Wanamaker. Congress passed legislation in 1911 authorizing federal land for the memorial, and President Taft personally attended the groundbreaking ceremony on February 22, 1913 (Washington's birthday) at Fort Wadsworth, Staten Island.

The proposed memorial would have been an enormous Egyptian Revival museum complex topped by a 70-foot neo-Aztec pyramid pedestal, surmounted by a 60-foot bronze statue of a Native American warrior facing seaward. The total structure would have stood taller than the Statue of Liberty (which sat in the same harbor). Daniel Chester French, the sculptor of the Abraham Lincoln statue at the Lincoln Memorial, was selected to create the statue. Architect Thomas Hastings was chosen for the museum complex.

The groundbreaking ceremony attended by Taft included 32 Native American chiefs from various tribes. The cornerstone was laid. Then World War I broke out, public attention shifted, and Wanamaker (originally a funder, eventually a fundraiser) couldn't raise the remaining capital. He died in 1928. The memorial was officially abandoned in 1929.

9Mother's Memorial

In the 1920s, Daisy Breaux Calhoun of the Woman's National Foundation became obsessed with building a monument to American motherhood. Her husband Clarence Crittenden Calhoun was a wealthy Kentucky lawyer; the family lived in Washington's Rossdhu Castle, which Daisy designed (and which they lost during the Depression). The result, the proposed Mother's Memorial, was perhaps the most outsized never-built structure ever proposed for the National Mall.

The design by sculptor William Clark Noble called for a 297-foot-tall arch of white marble, set atop a football-field-length ziggurat of marble stairs. The arch would have been filled with a bas-relief showing mothers sending their sons to war and nursing wounded soldiers. Four allegorical statues would sit on columns surrounding the arch. On top of everything, a statuary scene with a "Mother" figure holding a "Torch of Enlightenment" and offering another torch to figures of "Young Manhood" and "Young Womanhood."

For comparison, the Lincoln Memorial is 99 feet tall. The proposed Mother's Memorial would have been three times that height, dominating the Washington skyline. The technical inclusion-on-this-list note is that this project never received a formal federal authorization the way some of our other entries did, but it did receive serious consideration from the US Commission of Fine Arts and the project was actively advanced for nearly a decade.

The project collapsed under a combination of factors:

• The US Commission of Fine Arts was, in the words of Smithsonian Magazine, "not too keen on the idea to begin with"
• The Great Depression made fundraising impossible after 1929
• A scandalous court case erupted in which sculptor Noble accused Calhoun of blackmail (later dropped)
• The original financial backer (Clarence Calhoun) lost interest

By 1933 the project was effectively dead. Daisy Calhoun never got her giant mother holding a torch.

10The Coolidge African American National Memorial

This one breaks your heart a little. On March 4, 1929 (his last day in office), President Calvin Coolidge signed Public Resolution 107 of the 70th Congress, creating the National Memorial Commission. The Commission was charged with designing and constructing a memorial building "as a tribute to the Negro's contribution to the achievements of America."

The memorial was to be a serious building, suitable for meetings of patriotic organizations, public ceremonies, exhibitions of art and inventions, and the display of statues and tablets. It would have been one of the most prominent federal monuments to African American contributions ever built. The 12-member commission included presidential appointees plus the Director of Public Buildings, the Architect of the Capitol, and the Treasury's Supervising Architect.

The federal government committed $50,000 in seed funding. That money was contingent on the National Memorial Association privately raising $500,000 in matching funds first.

11Theodore Bingham's White House Expansion

The White House you know today has the West Wing and East Wing extensions attached to the original residence. But that compromise structure almost didn't happen. In 1900, Army Engineer Colonel Theodore Bingham unveiled an enormous plan to expand the White House by attaching massive flanking two-story cylindrical wings with domes and lanterns patterned after those at the Library of Congress.

The model was displayed at the December 12, 1900 White House centennial reception. Bingham presented his design to McKinley personally. President McKinley was apparently intrigued. Architects across America were appalled. The American Institute of Architects roundly criticized the project.

McKinley was assassinated in September 1901. Theodore Roosevelt took office. Roosevelt decisively rejected the Bingham plan and instead hired the architectural firm McKim, Mead & White to do a more modest renovation. The result was the West Wing and East Wing as we know them today, built between 1902 and 1909, which became the template for the modern White House.

Without Roosevelt's decision, the White House would have looked more like a small palace, with twin domed cylindrical wings flanking the original residence. The Bingham plan included substantial portions of what later became the National Mall expansion under the McMillan Plan.

12Paul Pelz's Presidential Palace

By the late 1800s, the White House had become genuinely too small for the executive functions of a growing federal government. Congress seriously considered replacing it entirely. In 1898, two competing designs for a brand-new presidential mansion were submitted: one by Paul J. Pelz (best known as co-architect of the Library of Congress) and another by Franklin W. Smith.

Pelz proposed a palatial executive mansion to be built on Meridian Hill (now part of Malcolm X Park / Meridian Hill Park). The design was, charitably, palatial. Less charitably, it looked like something a European monarch would build. Smith's competing design was even more aggressively monarchical.

Congress, true to American republican instincts, turned both proposals down. The decision was eventually reached to expand and renovate the existing White House rather than build a new one. (This is the decision that led to the Bingham plan at #11, then to Roosevelt's rejection of Bingham, then to the McKim West Wing.)

13Gold Star Mothers National Monument

This is the most recent example on our list, and it's a textbook case of how the modern federal memorial process can quietly kill a project. In January 2013, Congress authorized the Gold Star Mothers National Monument Foundation to construct a memorial on federal land in Washington DC honoring mothers whose children died in defense of the United States.

The authorization was included in the National Defense Authorization Act for Fiscal Year 2013, signed by President Obama. The memorial would have honored Gold Star Mothers, an organization formed after World War I for mothers who lost children in military service. Under the rules of the Commemorative Works Clarification and Revision Act of 2003, the foundation had seven years (until January 2, 2020) to raise the necessary funds and complete the design approval process.

They didn't.

The seven-year clock ran out without the foundation completing the required steps. On January 2, 2020, the congressional authorization automatically lapsed. The Gold Star Mothers National Monument became, officially, a never-built federally-approved project.

14The 1924 Columbia Island Arch (and its 2026 Trump-arch ghost)

This is the project that got me thinking about this whole topic in the first place.

In 1924, the Arlington Memorial Bridge Commission released a report planning the entire approach to Arlington National Cemetery from Washington DC. The bridge would be low and ceremonial. At Memorial Circle on Columbia Island, the report called for two ceremonial columns, each 166 feet tall, to serve as vertical markers framing the approach to the cemetery. Congress approved the Arlington Memorial Bridge in 1925.

The bridge got built between 1926 and 1931. The columns did not. They were quietly dropped from the project. The Commission considered them aesthetically unnecessary and never came back to fund them. From 1925 through 2025, the Memorial Circle sat without the planned columns, and nobody much cared.

Then in October 2025, at a White House donor dinner, President Trump unveiled his plan for a 250-foot triumphal arch in the same general location. As Newsweek reported, the renderings filed with the Commission of Fine Arts in April 2026 show the main arch mass at 166 feet tall - the exact same height as the never-built 1924 columns. The remaining 84 feet of height comes from gilded statuary on top (a Lady Liberty-like figure with a torch, two eagles, four lions at the base).

Why does that 166-foot figure matter? Because the Trump administration is using the 1924 column authorization as legal cover for building the new arch without seeking fresh Congressional approval. Justice Department lawyers wrote in court filings that "Congress authorized the arch project when it approved the design set out in Arlington Memorial Bridge Commission's report." Interior Secretary Doug Burgum cited the 1924 plan directly at the April 2026 Commission of Fine Arts meeting.

Whether the 1924 column proposal can legally justify a much larger structure of an entirely different type (single arch versus paired columns, twin structures versus single, ceremonial framing versus dominant central mass) is the legal question now in front of the federal courts. The 1924 columns themselves remain on this list as a federally-approved-but-never-built project. The 2026 arch is a separate proposed project. Whether it gets built will probably be determined by what happens in court over the next several months.

15Clark Mills's Equestrian Lincoln Memorial

This is the oldest project on our list, and arguably the strangest. Just two years after Lincoln's assassination, in 1867, sculptor Clark Mills (who had designed the equestrian statue of Andrew Jackson in Lafayette Square) proposed to build next to the US Capitol a 70-foot bronze structure featuring 36 separate figures, including six on horseback.

The Lincoln Monument Association, formed in 1867 to advocate for a federal Lincoln memorial, supported the design. The proposal received serious congressional consideration. It was sufficiently advanced that, when the Washington Post historical archives describe Pope's 1912 pyramid Lincoln Memorial as "not the craziest idea pitched a century ago," the historians are specifically thinking of Clark Mills's 36-figure equestrian Lincoln.

The Mills design never received the formal federal authorization that the eventual Lincoln Memorial did under the 1911 act. But the Lincoln Monument Association's advocacy work was the direct ancestor of the federal effort that ultimately produced the Henry Bacon temple in 1922. So in a meaningful sense, this is the first proposed federal Lincoln memorial: a 70-foot bronze chaos of Lincoln on horseback, surrounded by 36 figures, parked next to the Capitol building.

What do all 15 of these projects have in common?

Looking at the full list, there are some patterns worth pulling out.

The science and infrastructure megaprojects fail because of cost overruns and shifting political winds. The SSC, Yucca Mountain, Auburn Dam, NAWAPA, Project Plowshare, and Project Iceworm all died because original cost estimates ballooned, political coalitions shifted, and the projects became politically expensive to defend. The SSC was killed two years after Reagan-era Republican enthusiasm for big science gave way to early-Clinton fiscal restraint. Yucca Mountain was killed after Harry Reid became Senate Majority Leader. Auburn Dam was killed when a 1976 earthquake undermined the geological assumptions and the environmental movement gathered force in the 1980s.

The monumental memorials fail because of money, scandal, or war. The Mother's Memorial died in scandal and the Depression. The National American Indian Memorial died because World War I sapped public attention and Wanamaker died before completion. The Coolidge African American Memorial died in the 1929 stock market crash. The Gold Star Mothers Memorial died because the foundation couldn't raise private money within the seven-year window.

The presidential building projects fail because new presidents make different choices. Roosevelt rejected Bingham's White House expansion. Congress rejected Pelz's Meridian Hill palace. The Mills equestrian Lincoln was passed over for Bacon's temple. American executive architecture is unusually subject to presidential and congressional veto, because each administration has the power to redesign the next round.

And the Trump arch is using the failure of the 1924 columns as its own ammunition. The fact that the 1924 columns were never built is, in 2026, being used by the federal government to argue that a different, much larger monument can be built today without fresh authorization. That's a novel and aggressive legal theory. It's also, in a way, the spirit of this whole article: never-built American projects don't just disappear. They sit in the legal and architectural record, waiting for someone with a new idea to use them.

Sources: US Commission of Fine Arts (2026); Washington Post (May 20, 2026); Newsweek (May 21, 2026); Congressional Research Service report via Rep. Steve Cohen (May 2026); White House Historical Association; Boundary Stones (WETA, May 2025); Smithsonian Magazine; Library of Congress Prints and Photographs Division; Lawrence Livermore National Laboratory (Plowshare program history); National Archives Prologue blog (John Russell Pope's Lincoln Memorial designs, 2014/2022); Physics Today (SSC retrospective, 2016); Scientific American; Texas Monthly; US Department of Energy Office of Inspector General Report DOE/IG-0389 (1996); Government Accountability Office reports GAO/RCED-94-153 and T-RCED-92-48; Senator Catherine Cortez Masto press releases (2018); High Country News (Yucca Mountain coverage); BuzzFeed News (NAWAPA, September 2015); American Enterprise Institute (Megaprojects analysis, 2024); Wikipedia: Project Iceworm, Camp Century, National American Indian Memorial, Auburn Dam, Yucca Mountain nuclear waste repository, Superconducting Super Collider, Project Plowshare, Gold Star Mothers National Monument, North American Water and Power Alliance.Note on dollar figures: Cost estimates for partially-completed federal projects are notoriously difficult to verify precisely. Where we cite a figure like "$15 billion sunk into Yucca Mountain," we are using the Government Accountability Office's 2013 research-expenditure estimate, which Senator Cortez Masto repeated in 2018. Some inflation-adjusted estimates run as high as $19-22 billion. The $96 billion figure cited in some places is the Department of Energy's 2008 estimate of the FULL lifecycle cost to complete construction and operate through 2133, not the money already spent. All dollar figures should be treated as good-faith approximations rather than precision accounting.DaveManuel.com is an editorial finance, history, and politics site. This article is provided for informational and educational purposes only.