- Rank and organization: Second Lieutenant, U.S. Army, 115th Infantry, 29th Division.
- Pace and date: Bois-de-Consenvoye, France, 8 October 1918.
- Entered service at: Los Angeles, Calif.
- Birth: Middleboro, Mass.
- G.O. No.: 50, W.D., 1919.
Citation: While leading his platoon against a strong enemy machinegun nest which had held up the advance of 2 companies, 2d Lt. Regan divided his men into 3 groups, sending 1 group to either flank, and he himself attacking with an automatic rifle team from the front. Two of the team were killed outright, while 2d Lt. Regan and the third man were seriously wounded, the latter unable to advance. Although severely wounded, 2d Lt. Regan dashed with empty [M1911] pistol into the machinegun nest, capturing 30 Austrian gunners and 4 machineguns. This gallant deed permitted the companies to advance, avoiding a terrific enemy fire. Despite his wounds, he continued to lead his platoon forward until ordered to the rear by his commanding officer.
Congressional Medal of Honor Citations, U.S. Army Center of Military History