Marshall was assigned to the War Plans Division on the War Department staff, and he was subsequently appointed as the Army’s Deputy Chief of Staff. When Chief of Staff Malin Craig retired in 1939, Marshall became acting Chief of Staff, and then Chief of Staff. He served as Chief of Staff until the end of the war in 1945.

As Chief of Staff, Marshall organized the largest military expansion in U.S. history, and received promotion to five-star rank as General of the Army. Marshall coordinated Allied operations in Europe and the Pacific until the end of the war; in addition to being hailed as the organizer of Allied victory by Winston Churchill, Time magazine named Marshall its Man of the Year for 1943. Marshall retired from active service in 1945, but remained on active duty, a requirement for holders of five-star rank. In late 1945 and early 1946 he served as a special envoy to China in an unsuccessful effort to negotiate a coalition government between the Nationalists of Chiang Kai-shek and Communists under Mao Zedong.

As Secretary of State from 1947 to 1949, Marshall received credit for the Marshall Plan for Europe’s post-war rebuilding, the success of which was recognized with award of the 1953 Nobel Peace Prize. After resigning as Secretary of State, Marshall served as chairman of American Battle Monuments Commission and president of the American National Red Cross. As Secretary of Defense at the start of the Korean War, Marshall worked to restore the military’s confidence and morale at the end of its post-World War II demobilization and then its initial buildup for combat in Korea and operations during the Cold War. After resigning as Defense Secretary, Marshall retired to his home in Virginia. He died in 1959 and was buried at Arlington National Cemetery.