Henry Knox Thatcher (26 May 1806 – 5 April 1880) was a rear admiral in the United States Navy, who served during the American Civil War.
Early life and career
Thatcher was born in Thomaston, Massachusetts (after 1820 in Maine) to Ebenezer Thatcher and his wife, Lucy (daughter of Major General Henry Knox and Lucy Flucker Knox). Appointed to the U.S. Military Academy at West Point in 1822, Thatcher was absent on sick leave for most of the first year and resigned in April 1823. He then received an appointment as a midshipman in the Navy
Thatcher spent most of the next four years on board the frigate in the Pacific. and served aboard the schooner in Chesapeake Bay. He commanded the screw frigate in the North Atlantic Blockading Squadron in 1864–1865, and a division of Admiral Porter's squadron at the two battles of Fort Fisher in December 1864 and January 1865. Thatcher was then appointed to command of the Western Gulf Squadron, immediately commencing operations in cooperation with General Canby, commander of the Army of West Mississippi, in the capture of Mobile, Alabama. After a brief and vigorous bombardment, Spanish Fort and Fort Blakeley were captured by the Union Army on 9 April 1865. With the key defences of the city lost, the Confederate troops evacuated Mobile on April 12. A formal surrender was demanded by General Granger and Acting-Rear Admiral Thatcher, and possession taken of the city.