High Quality Content by WIKIPEDIA articles! The 45th New York Volunteer Infantry Regiment, also known as the 5th German Rifles, was an infantry regiment that served in the Union Army during the American Civil War. It was composed almost entirely of German immigrants. Formed approximately five months after the start of hostilities, the unit`s service spanned almost the entirety of the war, and it saw action in several of the war`s noteworthy battles, in both the Eastern and Western Theaters.