 Complete the following phrase:  In 1862 Thomas was sent to serve in the Western Theater, and was given command of the artillery belonging to a brigade in the Army of Mississippi as of March 18. Eight days later Thomas was appointed assistant inspector general of the brigade, a post he held until that summer. Assigned to the staff of Maj. Gen. Jones M. Withers, Thomas fought at the Battle of Shiloh on April 67, performing a commendable part in the battle... In July he was assigned command of the armys Reserve Corps artillery, a position Thomas would hold for the rest of the year. He also participated in the 