Theodore Henry Peters was born around 1823. By the early 1860s, he was living in Philadelphia, Pennsylvania.
He received a commission as captain of Company D of the 31st Pennsylvania Infantry, and he mustered in on August 16, 1861. The regiment later became the 82nd Pennsylvania Infantry, and it took part in the Peninsula campaign, the Battle of Seven Pines, the Seven Days’ Battles, the Battle of Antietam, the Battle of Fredericksburg, the Battle of Chancellorsville, and the Battle of Gettysburg. He was discharged for disability on December 7, 1863.
He died sometime after January 1867.