Lucian King Truscott, Jr., was born January 9, 1895, in Chatfield, Texas. He enlisted in the Army upon America's entry into World War I. He was selected for officer training and was commissioned in the cavalry in 1917.

He served in a variety of cavalry assignments during the interwar period and served as an instructor at both the Cavalry School and the Command and General Staff School. Early in World War II he joined Lord Mountbatten's combined staff where he developed the Ranger units for special operations.

On 2 September 1944, Truscott was promoted to lieutenant general (3-stars) and in October he was appointed commander of the newly formed Fifteenth Army, which was largely an administrative and training command.

He led his Rangers in combat at Dieppe and in Morocco and then began his assent through the various levels of major combat command. He was the commanding general of the 3d Infantry Division (Mar. 1943) in Sicily and Italy, VI Corps (Feb. 1944) in Italy and Southern France, Fifteenth Army (Oct. 1944), Fifth Army (Dec. 1944), and Third Army (Oct. 1945). 

In the post-war period he commanded occupation forces in Bavaria and served in various advisory positions, enabling the Army to capitalize on the great wealth of his experiences. General Truscott was a reliable, aggressive, and successful leader.

General Truscott received the Army's second-highest decoration, the Distinguished Service Cross, for valor in action in Sicily on July 11, 1943, the second day of the invasion. General Truscott's other decorations include the Army Distinguished Service Medal with Oak Leaf Cluster, the Navy Distinguished Service Medal, the Legion of Merit and the Purple Heart.

General Truscott died 12 September 1965, in Alexandria, Virginia. On 29 April 1966, Truscott Hall, a bachelor officers' quarters at the Army War College, was named after him.