At 15 years of age tried to join (along with his twin brother John) his brother's (Gustavus Brown Wallace) regiment but was refused due to age. Two years later (23 November 1779) he was successful—was commissioned Lieutenant in the 8th Regular Virginia Line and served til 19 November 1781 when he received orders to join the Southern Army in the Carolinas. He resigned in November of 1792.

On 22 October 1790, for his services he received from Virginia 2,666 and two-thirds acres of land. His heirs presented claim for compensation for his services to the 22nd U.S. Congress, 1st Session, which was approved by the 23rd Congress, on 30 June 1834.