1777 – Gaines was born in Culpeper County, Virginia on the 20th of March.
1799 – He joined the United States Army.
1807 – He was promoted to first lieutenant.
1810 – He studied law after he left the army.
1812 – He entered the army and was appointed Army Major of the Eighth U.S. Infantry. He was promoted to Lieutenant Colonel in the Twenty Fourth U.S. Infantry.
1813 – He was promoted to colonel and commanded the Twenty Fifth Infantry with distinction at the Battle of Crysler’s Farm. He was promoted again to Adjutant General.
1814 – He was promoted brigadier general of regulars on the 9th of March. He was awarded the Thanks of Congress, a gold medal, and a brevet promotion to major general after he defended Fort Erie.
1836 – He assumed command of the Southwest Military District.
1849 – He died at New Orleans, Louisiana on the 6th of June.