During the American Revolutionary War, he was in the battalion of General Robert Howe. On January 9, 1778, Walton received a commission as colonel of the First Georgia Regiment of Militia. During the Battle of Savannah in 1778 led by Archibald Campbell, Walton was injured in the battle and taken prisoner. He was hit in the thigh by a ball that threw him from his horse. He was subsequently captured by the British, who allowed his wound to heal before sending him to Sunbury Prison, where other colonial prisoners were held. Walton was eventually exchanged in October 1779.