The 503rd Infantry Regiment and the 2nd Infantry Division are both formations of what military branch
2nd Infantry Division (United States) The 2nd Infantry Division ("Indianhead"; "2ID," "2nd ID", or "Second D") is a formation of the United States Army. Its current primary mission is the defense of South Korea in the initial stages of an invasion from North Korea until other American units can arrive. There are approximately 17,000 soldiers in the 2nd Infantry Division, with 10,000 of them stationed in South Korea, accounting for about 35% of the United States Forces Korea personnel.
222nd Infantry Regiment (United States) The 222nd Infantry Regiment was an infantry regiment of the United States Army, AUS. It served in the 42nd Infantry Division for the duration of the Second World War, and was then deactivated. The regiment distinguished itself in battle against the Wehrmacht and earned the Presidential Unit Citation for courageous action.