sentences:  By the start of the Civil War, at the age of 63, Abercrombie was one of the oldest field officers in both the Union and Confederacy.He served as the commanding officer of the 7th U.S. Infantry in Minnesota with the full rank of colonel in the Regular Army.Promoted to brigadier general of Volunteers in the Union Army on August 31, 1861, Abercrombie commanded troops under his father-in-law Robert Patterson in the Shenandoah Valley and at the Battle of Falling Waters.