The Manhattan Project

Description

Because the mission to create the atomic bomb was top secret, General Leslie Groves decided to follow the tradition of Corps of Engineers projects for the city in which they were located.

The Manhattan Project was the U.S.-led effort during WWII to develop nuclear weapons, involving the U.K. and Canada. Directed by Major General Leslie Groves, with physicist J. Robert Oppenheimer leading the Los Alamos Laboratory, the project created two atomic bombs, "Little Boy" (uranium-235) and "Fat Man" (plutonium). It employed 130,000 people and cost $2 billion (equivalent to $27 billion today).

Established, June, 1942

The Manhattan District was created as part of the U.S. Army's role in the Manhattan Project, under Colonel James C. Marshall. Initially headquartered in New York, the project later expanded to various sites, including one near Knoxville, Tennessee, for its proximity to resources like power and water. The project faced budget challenges, but high-priority status enabled it to secure the resources necessary for constructing production plants. The district eventually oversaw operations across multiple locations and was later led by Colonel Leslie Groves. NYC is where the North Atlantic Division of the Army Corps of Engineers was headquartered at the time and where the project got its name. Built in 1930, the building is now occupied by office, retail, and residential spaces.

Selected, Sept 19, 1942

The next decision was to select a not too densely populated remote location, away from potential German or Japanese bombs. After taking over the project, General Leslie Groves visited Tennessee with Colonel James Marshall and approved the site. In September 1942, the Corps of Engineers acquired 56,000 acres for $3.5 million, forcing 1,000 families to vacate, despite protests and legal challenges. The site became the Clinton Engineer Works (CEW), later known as Oak Ridge. It housed uranium production facilities and a residential community for 13,000, built by Skidmore, Owings & Merrill. By May 1945, Oak Ridge’s population peaked at 75,000, with 82,000 workers employed at CEW.

Relocated, Dec, 1942

The idea of locating Project Y at Oak Ridge was considered, but a more remote location was chosen, following J. Robert Oppenheimer's suggestion. He recommended the area near Los Alamos, New Mexico, where he had a personal ranch. After a site visit on November 16th, 1942, the location was approved, and work began that December. Although it was initially meant to be a military lab, the University of California was contracted to operate the facility.

Surrendered, Aug 15, 1945

The preparations for the atomic bombings involved modifying B-29 bombers to carry the nuclear bombs and forming the 509th Composite Group under Colonel Paul W. Tibbets for the mission. Test drops of practice bombs were carried out, and bomb components were transported to Tinian Island. The bombings of Hiroshima and Nagasaki caused massive destruction and casualties. Following the bombings, Japan surrendered ending World War II. These events sparked ongoing debates about the necessity and ethics of using the bombs.

Ended, 1947

The project ended with the creation of the U.S. Atomic Energy Commission.

Factoids

Aug 6, 1945-The bombings of Hiroshima.

Aug 9, 1945-The bombings of Nagasaki.

Related People & Organizations

Harry S. Truman,Harry S. Truman authorized the use of atomic bombs on Hiroshima and Nagasaki in August 1945 to end World War II, following the successful Trinity test. Unaware of the top-secret Manhattan Project until after FDR’s death, Truman was briefed in April 1945, subsequently establishing the Interim Committee and overseeing the transition to civilian control with the 1946 Atomic Energy Act.

Franklin D. Roosevelt,President Franklin D. Roosevelt authorized the Manhattan Project in June 1942 to develop the world’s first atomic weapons, driven by fears of a Nazi German nuclear program. The top-secret, $2 billion effort spanned 37 locations, most notably Hanford (WA), Los Alamos (NM), and Oak Ridge (TN), employing over 130,000 people

Related Sites

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Columbia University-Multiple buildings at Columbia University were key to the Manhattan Project. Schermerhorn and Pupin Halls housed Professor John R. Dunning's team, where they built the Cyclotron that enabled nuclear fission. This Cyclotron is now part of the Smithsonian's collection. The Nash Garage Building, a former car dealership, was used by researchers like Lawrence S. O’Rourke to develop materials for the K-25 plant at Oak Ridge. After the war, Columbia's Prentis Hall became a nuclear testing laboratory involved in the "Atoms for Peace" initiative.

Woolworth Building-The Kellex Corporation had its headquarters inside the Woolworth Building, a 1920s skyscraper in Lower Manhattan constructed by Five-and-Dime millionaire Frank Woolworth and dubbed “The Cathedral of Commerce.” The Kellex Corporation was a clandestine off-shoot of the M.W. Kellogg Company, a chemical engineering company based in Jersey City. The company was chosen to design the K-25 plant in Tennessee and to develop processes and equipment to produce enriched uranium through gaseous diffusion. The K-25 name for the Oak Ridge site took its “K” from “Kellog” and “25” from the type of uranium used in the project.

Shinran Shonin-The Shinran Statue on 105th Street and Riverside Drive, a survivor of the Hiroshima blast, stands in front of the New York Buddhist Church, where an annual remembrance service to the atomic bombings of Hiroshima and Nagasaki are held.

Timeline

1942+ 2

Images

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Images

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A Award Pin 1945 Oak Ridge

United States Department of Energy

1942 - Established

2 Results,Show less

1942 - Established - Images

2 Images,Show less

1939

The cyclotron built by Dunning in the basement of Columbia’s Pupin Hall

Columbia University

The Nevis cyclotron

New York Times

1942 - Selected

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1942 - Selected - Images

5 Images,Show less

1945

Shift change at the Y-12 uranium enrichment facility

Ed Westcott

Alpha 1 racetrack, Uranium 235 electromagnetic separation plant, Manhattan Project, Y-12 Oak Ridge

Internet Archives

1943

The Calutron Girls were young women who monitored calutron control panels at Y-12.

Ed Westcott, American Museum of Science and Energy

Oak Ridge K-25 plant

Ed Westcott, American Museum of Science and Energy

The S-50 plant is the dark building to the upper left behind the Oak Ridge powerhouse (with smokestacks).

Ed Westcott, National Museum of Nuclear Science and History

1942 - Relocated

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1942 - Relocated - Images

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1945

A row of Thin Man casings

Public Domain

1945

Remote handling of a kilocurie source of radiolanthanum for a RaLa Experiment at Los Alamos

Los Alamos National Laboratory

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