Born in Pennsylvania, Marshall was educated at the Virginia Military Institute where he graduated in 1901. During World War I he was stationed in France and won acclaim for his direction of the St. Mihiel and Meuse-Argonne offensives. After World War I he was a high-level aide to General John J. Pershing. Prior to the outbreak of World War II he progressed steadily from assistant chief-of-staff of the U.S. Army (July, 1938) to deputy chief of staff (October, 1938), to chief of staff the following year. In 1944, Marshall was promoted to General of the Army.

After the second World War, President Truman made Marshall his secretary of state. Marshall was strongly anti-communist and his staunch anti-Soviet policy laid much of the foundation for the ensuing Cold War. The Truman Doctrine, providing aid to nations to fight communism, and the Marshall Plan, reconstructing the demolished European community, were both implemented during Marshall's tenure at the U.S. State Department. .

Initially, Marshall resigned from government service in 1949, but was called back to serve briefly as secretary of defense during the Korean conflict. He retired permanently in 1951. In 1953, Marshall won the Nobel Prize for Peace for his efforts in Europe.