51^st Armored Infantry Regiment

The 51st Armored Infantry Regiment was activated at Pine Camp, New York, on April 14, 1941, as the 51st Infantry Regiment (Armored), assigned to the 4th Armored Division. It became the 51st Armored Infantry Regiment on January 1, 1942, as the Army standardized armored infantry designations during the expansion of the armored force. The regiment trained in the United States, moving from Pine Camp to the Tennessee Maneuver Area in September 1942, then to Camp Young, California, in November, and to Camp Bowie, Texas, in June 1943.

The regiment did not deploy overseas or fight as a regiment. On September 10, 1943, at Camp Bowie, it was reorganized under the armored division's battalion-based structure. The regiment, less its 1st and 2nd Battalions, became the 51st Armored Infantry Battalion; the 1st Battalion became the 53rd Armored Infantry Battalion, and the 2nd Battalion became the 10th Armored Infantry Battalion. Those battalions, rather than the regiment, carried the infantry component of the 4th Armored Division into combat in France, Lorraine, the Ardennes, Germany, and Czechoslovakia.