The 324th Infantry Regiment was an infantry regiment of the United States Army first organized in August 1917 as part of the 81st Division, National Army. The 324th Infantry saw combat in the defense of the St. Die sector of Lorraine, and later took part in the closing stages of the Meuse-Argonne offensive of the First World War. The 324th Infantry was demobilized in June 1919, and subsequently reconstituted in the Organized Reserves in 1921, as part of the 81st Division. In 1942, the 324th Infantry was relieved from assignment to the 81st Division, allotted to the Army of the United States, and assigned to the 44th Infantry Division, a unit which fought as part of the 7th Army in France and Germany during World War II.