The Manhattan Project was one of the most expensive undertakings of World War II

Manhattan Project explained

Driven by fears of a Nazi nuclear bomb, the Manhattan Project united leading scientists to build the first atomic weapons. Its success ended World War II, caused catastrophic human loss, and launched the nuclear age that reshaped global politics and science.

The Manhattan Project employed hundreds of thousands of workers across the US

Between 1942 and 1945, the Manhattan Project relied on a vast workforce spread across secret sites. They performed roles ranging from scientific research to manual labor, motivated by patriotism, opportunity, secrecy, and wartime necessity.

Building the first atomic bomb required unprecedented coordination

Creating the first atomic bombs demanded breakthroughs in physics, engineering, and logistics—uniting elite scientists with tens of thousands of workers across the US. This in-depth history explains how the Manhattan Project overcame those challenges.

Interviews from the Manhattan Project

This is an archive of interviews with people who worked on and were impacted by the Manhattan Project, the World War II-era effort that resulted in the atomic bomb. Listen to the "father of the atomic bomb," Julius Robert Oppenheimer, describe his daily routine during the project, which he reports officially started Dec. 6, 1941. This archive also includes interviews with survivors of the Hiroshima and Nagasaki bombings.

Modern Marvels examines the Manhattan Project

This episode of the television program 'Modern Marvels' focuses on the Manhattan Project, combining archival footage and interviews with historians and scientists to shed light on one of the most ambitious military and scientific endeavors in human history.

Meet the the scientists of the Manhattan Project

This resource profiles the scientists behind the Manhattan Project—from Nobel laureates like Fermi and Bethe to controversial figures like Teller and Fuchs—showing how their ideas, rivalries, and choices shaped the development of the atomic age.

The Manhattan Project created secret cities that didn’t appear on maps

To maintain secrecy, the US built three remote research facilities and entire “secret cities” to house thousands of workers and families. These communities—home to tens of thousands—were omitted from official maps until after World War II.

Learn more about the three sites that powered the Manhattan Project

The Manhattan Project relied on three main sites: Oak Ridge, which enriched uranium; Hanford, which produced plutonium in large reactors; and Los Alamos, which designed and assembled the bombs—work that culminated in the Trinity nuclear test in 1945.

Spies working on the Manhattan Project propelled the Soviet bomb program

Soviet infiltration—most notably by Klaus Fuchs—smuggled detailed implosion-design and hydrogen‑bomb data from Los Alamos to Moscow, cutting the USSR’s development time by at least a year and enabling their first atomic test in August 1949.

Nuclear weapons in WWII

This 14-minute interactive documentary broaches the subject of the human cost of nuclear warfare. Comparing the number of deaths during World War II with the projected deaths of a nuclear exchange, the video can be paused to delve deeper into individual statistics, historical tidbits, and more data that shows the terrible price humanity would pay.

The atomic bombs dropped on Japan had massive human costs

The US atomic bombings of Hiroshima and Nagasaki in August 1945 killed around 210,000 people—more than 38,000 of them estimated to be children—with tens of thousands more later dying from radiation-linked illnesses, leaving lifelong trauma and increased cancer risks.

How much did WWII cost?

Though it lasted fewer than four years, World War II was the most expensive war in United States history, according to this infographic. Read through it to see how much WWII cost and learn about the consequences of financing such an expensive conflict.

Penicillin production was just behind the atom bomb in wartime priorities

By 1943, the US War Department made penicillin its second-highest priority—just after the Manhattan Project. Producing enough of the antibiotic for the D-Day invasion became a central mission of Allied science and industry.

The incredibly advanced engineering of the B-2 Bomber

B-2 Bombers are the world's most expensive plane, coming in at a cost of $2B per aircraft. There are roughly 20 in the world, all in use by the United States Air Force. They are known for their single-wing profile, allowing for stealth and the ability to transport some of the world's largest bombs.

View the most expensive materials on Earth, led by those forged in particle accelerators

Californium-252—valued at $27.8M per gram, as of 2025—is far rarer and more valuable than gold, silver, or diamonds due to production and transportation costs. The most expensive substance ever found or created is antimatter, costing approximately $62.5T per gram.

A US project proposed a 10-gigaton nuclear bomb capable of global devastation

Planned in the early 1950s by US scientists, Project Sundial aimed to create a 10-gigaton thermonuclear bomb—hundreds of times more powerful than any weapon ever built. Had it been tested, it was expected to cause global environmental catastrophe.

Only 34% of Americans supported the Apollo program in 1967

After a fire killed three astronauts on the launchpad of Apollo 1, the public became ambivalent about funding the multibillion-dollar program until the successful moon landing in 1969. The landers alone cost $388M, while each spacesuit cost $100,000.

A Manhattan building doomed to collapse was saved in secret

After completing the Citicorp Center, its engineer realized that cost-cutting measures to use bolted instead of welded joints made the building vulnerable to collapse under quartering winds. For three months, crews worked in secret at night to reinforce the building under Project Serene.

The Marshall Plan aimed to rebuild Europe and limit Soviet influence

Launched in 1948, the Marshall Plan provided over $12B (roughly $150B today) in US aid to help rebuild Western Europe. While framed as economic recovery, it also served as a Cold War tool—tying countries to the US and excluding the Soviet bloc.

The Washington Monument was completed in 1884 after nearly 40 years of delays and funding shortages

At the time of its completion, the Washington Monument stood as the tallest building in the world. Its construction stalled for decades due to political disagreements and the Civil War. The 555-foot obelisk cost nearly $1.2M to build (around $40M in today's dollars).

Simulate the impact of an antimatter bomb around the world

Using "Total Annihilator," users can click on a location on the map, select the antimatter mass, and the observation altitude before detonating the bomb. Scrolling through the left sidebar reveals the impacts of the detonation, including the sizes of the resulting fireball and thermal pulse, the spread of ionizing radiation, and the atmospheric effects.

The 1956 Federal-Aid Highway Act spent $25B to build 41,000 miles of freeway

Sold to Congress as a national defense measure, the Interstate Highway Act committed the federal government to covering 90 cents of every dollar spent on a 41,000-mile freeway network, a subsidy that reshaped American cities and supercharged car dependency.

The $3B project scientists called 'junk'

In 1990, scientists set out to map all of human DNA. A $3B bet many called "junk." But the Human Genome Project's radical transparency and a race with a private company sped it to completion in just 13 years. Today, that once-contested map underpins nearly every breakthrough in genetics and personalized medicine.

Visualizing the AI investment wave

This data visualization from Reuters shows how massive AI investment has become by December 2025—revealing that, in today’s dollars, spending has surpassed the combined total of the Apollo program and the Manhattan Project.

Before the current East Wing ballroom project, only two White House renovations in the past 100 years cost more than $10M.

In 1984, Operation Smash Hit intentionally crashed a 239-ton train into a nuclear waste canister at 100 miles per hour to prove the canister's safety, which remained completely intact and lost just 0.29 of its 100 pounds of pressure.

Watch a visualization of the construction of Chernobyl's sarcophagus

Built to contain the remains of Reactor 4 after the nuclear disaster, the "shelter structure" was constructed from about 400,000 cubic meters of concrete—enough to fill 160 Olympic-sized swimming pools. Construction required vehicles and cranes modified with special shielding to protect workers.

While atoms are normally made of protons, neutrons, and electrons, exotic ones have been built with antimatter—alternate versions of normal matter that live for fractions of a second and are about a billion times as rare.

How fusion—which releases energy when two lighter atoms combine to form a heavier atom—differs from fission

The most expensive ad of all time was for Chanel No. 5 perfume and cost roughly $33M to produce in 2004—about $57M in today's dollars.

At the beginning of the 20th century, a group of young men ate standard American food—replete with food additives like borax and formaldehyde—as part of government research to better understand food safety.

Roughly 43 million US borrowers owe roughly $1.7T in student debt, the second-largest source of consumer debt behind mortgages.

In 1915, workers recovered a submarine-like vessel from the Chicago River, prompting fears of German espionage

Experimental hantavirus vaccines and therapies, still under development, have long been funded by the US military.

Explore an interactive map of battles from the American Revolution, along with detailed summaries of each engagement

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

In 2019, a laptop loaded with six of the worst malware in history and described as 'an exhibit of historical weaponry' sold for $1.3M.

View the ten deadliest tornadoes in US history.

Massive 3D printers have been used to build homes by stacking layers of 'concrete toothpaste,' a fire-resistant material that effectively insulates against outside noise.

Explore the archaeological treasures of Pompeii, the city buried under volcanic ash when Mount Vesuvius erupted in 79 CE.

Fireworks make a loud booming sound after exploding due to air expanding faster than the speed of sound.

Before writing 'Walden,' transcendentalist Henry David Thoreau nearly burned down his hometown with a campfire that grew out of control.

The name 'Silicon Valley' arose from the founding of Shockley Semiconductor Laboratory in Fairchild Semiconductor in 1956-57, founded near Stanford University in Palo Alto

Use this tool to calculate the dollar value of your parental mental load, from meal planning to coordinating after-school care, then see resources that help generate solutions.

The Russia-Ukraine conflict is the largest ground war in Europe since World War II in terms of casualties, forces mobilized, and displacement of civilians.

The first image of a black hole was captured by creating an Earth-sized virtual observatory from a network of eight radio telescopes.

See the most iconic photos from four decades of LIFE magazine

The US first hosted the World Cup in 1994, a tournament that lives in soccer infamy for its poor planning and the murder of Colombian player Andres Escobar, who'd accidentally scored on his own net.

An initial public offering or 'IPO' is the process of a private company becoming public by putting shares of the company on the stock market for purchase.

In 1939, baseball star Lou Gehrig delivered his inspirational 'Luckiest Man' speech after retiring due to the health condition that now bears his name.