William P. Grimes enlisted June 21, 1862 at Savannah with Capt. Banks. He was with the 21st Battalion, Georgia Cavalry, Co. B until through consolidation Company B of the 21st became Company E of the 7th Regiment, Georgia Cavalry.
Pvt. Grimes lost his horse during the battle at Trevillian Station, Va. on June 11, 1864. He received a pay for January and February on July 1, 1864 for a total of $24.00. In late fall of '64 he received a clothing issue.