The Manhattan Project, the top-secret American program that built the world's first atomic bomb, cost $27B in today's dollars and reshaped global power.

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

Building the first atomic weapons required hundreds of thousands of workers, vast secret facilities, and enormous spending. This 1998 study details the full cost of the Manhattan Project and compares it to other major US wartime expenditures.

The Manhattan Project operated at three key sites, each with a distinct role in building the first atomic bomb.

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.

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.

A four-part podcast traces how the Manhattan Project reshaped the world

This podcast series explores the origins of the Manhattan Project, its secret cities, and the scientists behind it—showing how the effort contributed to the end of World War II, launched the Atomic Age, and later led Oppenheimer to become a critic of nuclear weapons.

Meet the scientists who worked on the Manhattan Project.

The story of the Manhattan Project's unused demon core

A 3-inch, 14-pound sphere of nuclear reactive plutonium-gallium was set to be delivered to the Pacific Theater in 1945 to become the third atomic bomb dropped over Japan. When Japan surrendered, it was returned to Los Alamos in New Mexico for experiment, where two scientists would die testing whether the core could reach criticality—where it would release intense energy—via the use of a dense reflector. Watch the story here.

Robert Oppenheimer became the face of the Manhattan Project and the atomic bomb

This feature explores Oppenheimer’s early life, the traits that made him central to the development of the atomic bomb, and how his later years were marked by tension between pride in his work and opposition to weapons of mass destruction.

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.

Worried that Nazi Germany could weaponize nuclear fission first, Albert Einstein wrote a 1939 letter warning President Roosevelt about the possibility of atomic bombs—a decision he later regretted.

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.

On August 6, 1945, the Enola Gay dropped the first atomic bomb used in warfare on Hiroshima, Japan, killing at least 80,000 people instantly.

Oppenheimer reflected on the atomic bomb's legacy two decades later

In a 1965 CBS interview, J. Robert Oppenheimer discussed his role as Los Alamos director, expressing deeply mixed feelings about Hiroshima and Nagasaki and reflecting on how nuclear weapons had transformed the world since their first use.

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.

US secrets: Project Paperclip

The US launched Project Paperclip in 1946, covertly recruiting over 1,500 German scientists to advance American military and space programs. Among them was Wernher von Braun, a key architect of the V-2 rocket who later became instrumental in NASA’s Apollo missions. While these scientists accelerated technological breakthroughs, their recruitment raised moral debates about overlooking wartime affiliations in the name of progress—questions that remain unresolved today.

The Soviet Union’s surprising first atomic test ended the US nuclear monopoly

In 1949, the USSR successfully tested its first atomic bomb—ending the US monopoly on nuclear weapons and sparking an arms race that would define the Cold War.

The Gasbuggy Project detonated a nuclear bomb to fracture underground rock formations

Part of Project Plowshare—a program aimed at finding peaceful uses for nuclear devices—the 1967 experiment sought to extract natural gas trapped within shale in underground New Mexico. Gas radioactivity was found to be excessively high for use without expensive processing, and the project was deemed an economic failure.

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.

The discovery of the neutron paved the way for nuclear weapons

In 1932, James Chadwick discovered the subatomic particle when trying to explain the radiation emitted by beryllium after it was bombarded with alpha particles. The radiation’s ability to eject protons from a target suggested a chargeless particle with slightly more mass than a proton.

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.

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 first nuclear reactor was built three years after nuclear fission was discovered

After learning that large atomic nuclei release energy upon being split apart, scientists quickly researched how to control the reaction to make electricity. Fusion—combining small atomic nuclei—generates massive energy in stars and hydrogen bombs.

The origin of atmospheric science while testing nuclear weapons during the Cold War

The arms race between the US and the Soviet Union saw both countries stockpiling and detonating hundreds of bombs underground, underwater, and in the atmosphere. To better predict where nuclear fallout would travel after these tests, scientists developed models that would serve as a foundation for those used to explain atmospheric circulation.

The H-bomb is hundreds of times more powerful than the bomb dropped on Hiroshima

Unlike the atomic bombs dropped on Hiroshima, which relied on nuclear fission, the hydrogen bomb uses fusion to unleash vastly greater destructive power. Developed by both superpowers in the 1950s, it gave each the ability to destroy entire cities in seconds.

Cold War nuclear tests exposed thousands to atomic blasts

After World War II, nuclear powers conducted thousands of weapons tests. This video pairs archival footage with interviews of veterans who witnessed Pacific test explosions, capturing the scale, shock, and human experience of being near a nuclear detonation.

The threat of nuclear annihilation reshaped global diplomacy

The first use of atomic weapons introduced the possibility of a war with no survivors. This article examines how nuclear fear shaped Cold War diplomacy and continues to influence international relations today.

The US once had a plan to nuke the moon

In the 1950s, the US considered detonating a hydrogen bomb on the moon as part of a Cold War show of force. Known as Project A119, the classified plan aimed to create a visible explosion from Earth to signal American dominance in the Space Race.

The US once had a plan to nuke the moon

In the 1950s, the US considered detonating a hydrogen bomb on the moon as part of a Cold War show of force. Known as Project A119, the classified plan aimed to create a visible explosion from Earth to signal American dominance in the space race.

The dramatic story of the spies and scientists behind the atomic bomb

This podcast traces the dramatic origins of nuclear weapons—from the scientists racing to beat the Nazis in Season 1 to the Soviet spy who stole atomic secrets in Season 2.

During the Cold War, a mid-air fire led to a nuclear bomber crash in Greenland that left a piece of a hydrogen bomb missing to this day.

Before 1932, when particle accelerators were first used for nuclear research, scientists relied on naturally radioactive substances to advance their understanding of the atomic nucleus.

In 1962, the US detonated a nuclear weapon in space, which produced an electromagnetic pulse that disabled three low Earth orbit satellites and damaged electrical equipment in Hawaii.

See how global nuclear arsenals surged—then shrank—by country since 1945

Worldwide nuclear stockpiles peaked at over 60,000 warheads in the mid‑1980s during the US-Soviet arms race. Today, about nine nations collectively maintain roughly 12,000 warheads, with Russia and the US still holding the majority.

While both are nuclear weapons, atomic bombs release nuclear energy by splitting large atomic nuclei, whereas hydrogen bombs derive most of their energy from fusing heavy hydrogen isotopes.

The US space program was built on former Nazi expertise through Operation Paperclip

After WWII, the US secretly recruited over 1,600 German scientists, including ex-Nazis like Wernher von Braun. They repurposed V‑2 rocket technology to create NASA’s core capabilities—pivotal in the Saturn V and Apollo missions.

View the most expensive materials on Earth, led by antimatter and other elements forged in particle accelerators.

The death toll of the atomic bombings in Japan remains disputed, with estimates ranging from 110,000 to 210,000.

Through 2038, the Large Hadron Collider research program is expected to generate societal benefits of €25.6B, or €3.3B more than operating costs and investments.

South Africa: the only nation to build nuclear weapons—and dismantle them by choice

During the 1980s, South Africa secretly built six uranium "gun‑type" nuclear bombs. In the 1990s, the government dismantled all its weapons and joined the NPT in 1991—the only country to fully reverse its nuclear program.

Visualizing the chemistry of nuclear weapons

Nuclear weapons have devastating effects, but the science of how they work is atomically small. There are two main types of nuclear reaction: fission and fusion. The fission bomb produces immense energy by splitting an atom, the result of firing a...

J. Robert Oppenheimer’s grandson says his grandfather would back nuclear power

While the "father of the atomic bomb" referred to the bomb as "an evil thing," after the Manhattan Project, he also described nuclear energy’s potential as an environmentally friendly solution to address the world's energy problem.

The Tsar Bomba was the most powerful nuclear weapon ever tested

In 1961, the Soviet Union detonated AN602—known as the Tsar Bomba—the largest nuclear explosion in history. Newly released Russian footage starkly illustrates the unmatched destructive power of this nuclear weapon.

The discovery of nuclear fission was facilitated by the discovery of the neutron

The discovery of the neutron provided scientists with a particle that could penetrate the nucleus and advance atomic physics. Otto Hahn was the sole Nobel recipient for the discovery of fission, despite collaborating with Lise Meitner and Fritz Strassmann.

China doubled its nuclear stockpile between 2020 and 2025, with plans for further expansion.

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.

Okinawa’s ferocity convinced the US atomic bombs was necessary

The brutal 82-day Battle of Okinawa—where US forces suffered nearly 50,000 casualties and Japanese military and civilians lost over 200,000 lives—clinched the grim reality that a full invasion of Japan would be even bloodier. This stark lesson directly shaped American decisions to deploy atomic weapons, aiming to avoid a potentially catastrophic ground war on the Japanese mainland.

The Bomb-proof, Cold War-era New York data center inspiring spy movies

At 33 Thomas Street in Lower Manhattan, New York City, a 45-story concrete tower with no windows stands imperiously over the city. Inside, 18 floors of telecommunications technology have hummed for decades. The building's purpose—to protect US comms from nuclear fallout—and its design have played into spy movie plotlines. Dive into the building's curious role in pop culture with this long read.

For decades, the US has considered building a permanent nuclear waste repository

All nuclear waste would have been stored at Nevada's Yucca Mountain, but the Obama administration indefinitely stalled the project after intense community backlash. Spent fuel is now stored at more than 80 locations in 36 states, raising safety concerns.