Omar Nelson Bradley graduated from the U.S. Military Academy at West Point, New York in 1915, where he later taught mathematics. After years of administrative posts, Bradley was a brigadier general when the United States entered World War II. He commanded forces in North Africa and Sicily, then moved to command the American involvement in the D-Day invasion of 1944, ultimately liberating Paris, France from the German occupied forces. Quiet, polite and popular with enlisted men, Bradley has often been contrasted with his more colorful and blustery colleague, General George S. Patton, Jr. After the war, Bradley served in the Veterans' Administration and as the Chairman of the Joint Chiefs of Staff, retiring in 1953.