Leslie Groves

Leslie Richard Groves Jr. (17 August 1896 – 13 July 1970) was a United States Army Corps of Engineers officer known for two major achievements during World War II. He oversaw the construction of the Pentagon, the massive office building that became the headquarters for the United States War Department. Even more importantly, he directed the Manhattan Project, the secret research program that developed the atomic bomb.

Groves came from a military family and graduated from the United States Military Academy at West Point. Before taking charge of the Manhattan Project in 1942, he had experience with construction and planning, which helped him manage the enormous task of building facilities across the United States. He played a key role in choosing locations such as Oak Ridge, Tennessee, Los Alamos, New Mexico, and Hanford, Washington for research and production.

During the Manhattan Project, Groves was responsible for many critical decisions, including selecting the cities in Japan that would become targets. Though security was very tight, some secrets were passed to the Soviet Union by spies. After the war, he continued to lead nuclear weapons projects until 1947 and later worked for a private company, Sperry Rand. His leadership in creating the atomic bomb changed history forever.

Early life

Leslie Richard Groves Jr. was born on 17 August 1896 in Albany, New York. His father was a pastor who later became a United States Army chaplain. Because of his father's work, Groves grew up moving between many Army posts.

He attended Queen Anne High School and later tried to enter the United States Military Academy at West Point. Although he didn’t get in at first, he tried again and succeeded. He started at West Point on 15 June 1916. When the United States entered World War I in 1917, the training schedule was shortened. Groves finished fourth in his class and became a second lieutenant in the Corps of Engineers.

Between the wars

After finishing at West Point, Leslie Groves went to Camp A. A. Humphreys in Virginia. He then studied at the Engineer School and later commanded a company at Fort Benning, Georgia. He married Grace Wilson in 1922, and they had two children.

Groves served in Hawaii and helped build a trail. He also worked in Galveston, Texas, where he supervised important construction projects. Later, he led a survey team in Nicaragua and helped restore water supplies after an earthquake, earning an award for his efforts.

World War II

Construction Division

Leslie Groves was promoted to major in 1940 and soon became special assistant for construction to the Quartermaster General. His task was to help prepare facilities for the growing U.S. Army. Groves was known for his strong leadership and ability to get things done. He brought in reforms to improve construction processes, ensuring that camps and facilities were built efficiently and on time.

By the end of 1940, Groves took over the Fixed Fee Branch of the Construction Division. He introduced new methods to speed up construction, such as setting priorities for building and ensuring quick delivery of materials. His efforts helped mobilize over half a million men, with essential accommodations for two million men nearly complete by mid-December 1940.

Manhattan Project

The Manhattan Project was the top-secret effort to develop the atomic bomb during World War II. It began in 1942 under the leadership of General Groves. His role was to oversee the project, which involved scientists, engineers, and massive construction efforts. Groves worked tirelessly to ensure the project stayed on track, making critical decisions to secure resources and prioritize tasks.

Groves chose J. Robert Oppenheimer to lead the scientific team at Los Alamos in New Mexico. Despite concerns about Oppenheimer’s past ties to communist groups, Groves trusted his leadership abilities. The project faced many challenges, including securing raw materials like uranium and thorium. By 1945, the Manhattan Project had successfully developed atomic bombs, which were later used against Hiroshima and Nagasaki in Japan.

After the war

Responsibility for nuclear power and nuclear weapons was transferred from the Manhattan District to the Atomic Energy Commission on 1 January 1947. Groves was appointed chief of the Armed Forces Special Weapons Project in February 1947, which moved to the Pentagon in April.

In January 1948, the Chief of Staff of the United States Army, General of the Army Dwight D. Eisenhower, met with Groves to discuss his performance. Later that month, Groves received an honorary promotion to lieutenant general before retiring from the Army on 29 February 1948.

Later life

After his military service, Groves became a vice president at Sperry Rand and moved to Darien, Connecticut in 1948. He retired in 1961 and later wrote a book about the Manhattan Project called Now It Can Be Told.

In 1964, Groves returned to Washington, D.C. He passed away in 1970 after a heart attack. A funeral service was held at Fort Myer, Virginia, and he was buried at Arlington National Cemetery.

Legacy

Groves is remembered with a park named after him along the Columbia River near the Hanford Site in Richland, Washington. At the United States Military Academy, an award called the LTG Leslie R. Groves Award is given to the cadet who does the best in classes about nuclear engineering.

Many movies and shows have portrayed Groves. He was shown in a 1980 British TV series and in several films, including one in 1989 where Paul Newman played him, and a 2023 film directed by Christopher Nolan starring Matt Damon.

Dates of rank

Leslie Groves had a long and important career in the U.S. Army. He was promoted through the ranks, showing his skill and leadership over time. His work included overseeing the building of the Pentagon and leading the Manhattan Project during World War II, which were both huge and important tasks.

Insignia	Rank	Component	Date
No insignia	Cadet	United States Military Academy	15 June 1916
	Second Lieutenant	Regular Army	1 November 1918
	First Lieutenant	Regular Army	1 May 1919
	Captain	Regular Army	20 October 1934
	Major	Regular Army	1 July 1940
	Lieutenant Colonel	Regular Army	11 December 1942
	Colonel (temporary)	Army of the United States	14 November 1940
	Brigadier General (temporary)	Army of the United States	6 September 1942
	Major General (temporary)	Army of the United States	9 March 1944
	Brigadier General	Regular Army	6 December 1945
	Lieutenant General (honorary)	Regular Army	24 January 1948 (with effect from 16 July 1945, per Private Law 394-A of the 80th Congress)
	Major General	Retired	29 February 1948
	Lieutenant General (honorary)	Retired	29 February 1948