The 503rd Infantry Regiment and the 2nd Infantry Division are both formations of what military branch
503rd Infantry Regiment (United States) The 503rd Infantry Regiment, formerly the 503rd Parachute Infantry Regiment (PIR) and the 503rd Airborne Infantry Regiment (AIR), is an airborne infantry regiment of the United States Army. The regiment served as an independent regiment in the Pacific War during World War II; at Fort Campbell, Kentucky; in Okinawa, Japan; and in Germany. Regimental elements have been assigned to the 2nd Infantry Division, the 11th Airborne Division, the 24th Infantry Division, the 82nd Airborne Division, and the 173rd Airborne Brigade Combat Team. Regimental elements have participated in campaigns in the Vietnam War, Operation Enduring Freedom–Afghanistan, and Operation Iraqi Freedom. The regiment claims 15 Medal of Honor recipients: two from World War II, 10 from Vietnam, and three from Afghanistan. A parent regiment under the U.S. Army Regimental System. The regiment's 1st and 2nd Battalions are active, assigned to the 173rd Airborne Brigade, based at Caserma Ederle, Vicenza, Italy.
II Corps (Union Army) There were five corps in the Union Army designated as II Corps (Second Army Corps) during the American Civil War. These formations were the Army of the Cumberland II Corps commanded by Thomas L. Crittenden from October 24, 1862, to November 5, 1862, later renumbered XX Corps; the Army of the Mississippi II corps led by William T. Sherman from January 4, 1863, to January 12, 1863, renumbered XV Corps; Army of the Ohio II Corps commanded by Thomas L. Crittenden from September 29, 1862, to October 24, 1862, transferred to Army of the Cumberland; Army of Virginia II Corps led by Nathaniel P. Banks from June 26, 1862, to September 4, 1862, and Alpheus S. Williams from September 4, 1862, to September 12, 1862, renumbered XII Corps; and the Army of the Potomac II Corps from March 13, 1862, to June 28, 1865. Of these five, the one most widely known was the Army of the Potomac formation, the subject of this article.