My 3GRGR, who doesn't appear to ever have been naturalized as a U.S. Citizen, fought in the U.S. Civil war -- enlisting separately, twice.
He mustered in as a private on May 16, 1861 in Company K of the 16th New York Volunteer Infantry. He was wounded July 19, 1861, at the Battle of Bull Run (Manassas, Virginia). He avoided enemy fire, but caught his own bayonet in the ass while his Company was retreating over a hedge wall. He was honorably discharged on October 16, 1861.
A little over two years later, he mustered in as a private just after Christmas 1863 (December 28th). In this second tour, he was also a private but joined Company D of the 15th Cavalry Regiment, also of the New York Volunteers.
Four months after Lee surrendered to Grant, and three months after President Jackson declared an end to the insurrection, Julius mustered out on August 9, 1865.