US Army Major General. He was commissioned in the 1st Artillery Regiment in 1855 and was commended for his service in Florida during the Third Seminole War. He had been promoted to Captain by the start of the Civil War. While commanding Battery K, 1st Artillery he was cited for gallantry during the Peninsula Campaign, Antietam, and Gettysburg, earning brevets to Major, Lieutenant Colonel, and Colonel. He was appointed Colonel of the 2nd District of Columbia Infantry in 1865, and received a brevet promotion to Brigadier General at the end of the war. He remained in the Army, and by the start of the Spanish-American War he was a permanent Brigadier General. Graham was promoted to Major General of Volunteers, and commanded the Second Army Corps at Camp Alger, Virginia and Camp Meade, Maryland until reaching the mandatory retirement age of 64.

US Army Major General. He was commissioned in the 1st Artillery Regiment in 1855 and was commended for his service in Florida during the Third Seminole War. He had been promoted to Captain by the start of the Civil War. While commanding Battery K, 1st Artillery he was cited for gallantry during the Peninsula Campaign, Antietam, and Gettysburg, earning brevets to Major, Lieutenant Colonel, and Colonel. He was appointed Colonel of the 2nd District of Columbia Infantry in 1865, and received a brevet promotion to Brigadier General at the end of the war. He remained in the Army, and by the start of the Spanish-American War he was a permanent Brigadier General. Graham was promoted to Major General of Volunteers, and commanded the Second Army Corps at Camp Alger, Virginia and Camp Meade, Maryland until reaching the mandatory retirement age of 64.