Samuel Perry "Powhatan" Carter (August 6, 1819 – May 26, 1891) was a United States naval officer who served in the Union Army as a brevet major general during the American Civil War and became a rear admiral in the postbellum United States Navy.
He was the first and thus far only United States officer to have been commissioned both a general officer and a Naval flag officer.
C.f.: Joseph D.
Stewart, Major General, (United States Marine Corps) and Vice Admiral (United States Maritime Service), the USMS being a civilian agency.
C.f.
also: Rear Admiral and Brigadier General Raphael Semmes, Confederate States Navy and Army.