Complex sentence: His military service began in 1861, with his enlistment in the Union Army.Serving in Company A, Thirty-fourth Regiment, Indiana Volunteer Infantry, he was honorably discharged in September 1864.
Split into simpler sentences: His military service began in 1861 with his enlistment in the Union Army. Having served in Company A, Thirty-fourth Regiment, Indiana Volunteer Infantry, he was honorably discharged in September 1864.