The 56th Armored Infantry Regiment (AIR) traced its historical origin back to the 17th Infantry Regiment of Maj. Gen. George Sykes' 2nd Division of the 5th Army Corps, of the Army of the Potomac during the American Civil War. During World War I, soldiers from the reconstituted 17th Infantry Regiment were used to form the 56th Infantry Regiment on 15 May 1917, which was involved in the battle around Metz in Alsace-Lorraine. Ironically, when reconstituted as the 56th Armored Infantry Battalion during World War II, they were back in Alsace-Lorraine, fighting with the 12th Armored Division to liberate the same region of France from Nazi occupation in 1944-1945. On 7 July 1942, the unit was reconstituted as the 56th Armored Infantry Regiment and assigned to the 12th Armored Division, which was activated as a division at Camp Campbell, KY on 15 September 1942. On 11 November 1943 while at Watertown, Tennessee, the 12th Armored Division was reorganized and the 56th Armored Infantry Regiment was reorganized to form the 17th, 56th and 66th Armored Infantry Battalions (AIB).