John A. Dahlgren

John A. Dahlgren
Dahlgren in uniform, c. 1862
Birth nameJohn Adolphus Bernard Dahlgren
Nickname"Father of American naval ordnance"
Born(1809-11-13)November 13, 1809
Philadelphia, Pennsylvania, U.S.
DiedJuly 12, 1870(1870-07-12) (aged 60)
Philadelphia, Pennsylvania, U.S.
Buried
Laurel Hill Cemetery, Philadelphia, Pennsylvania, U.S.
AllegianceUnited States
BranchUnited States Navy
Service years1826–1870
RankRear admiral
CommandsSouth Atlantic Blockading Squadron
South Pacific Squadron
Bureau of Ordnance
Washington Navy Yard
Battles
SpouseMadeleine Vinton Dahlgren
RelationsJohn Vinton Dahlgren (son)
Ulric Dahlgren (son)
Charles G. Dahlgren (brother)

John Adolphus Bernard Dahlgren (November 13, 1809 – July 12, 1870) was a United States Navy officer who founded his service's Ordnance Department and launched significant advances in gunnery.

Dahlgren devised a smoothbore howitzer, adaptable for many sizes of craft and shore installations. He then introduced a cast-iron muzzle-loading cannon with vastly increased range and accuracy, known as the Dahlgren gun, that became the U.S. Navy's standard armament.

In the Civil War, Dahlgren was made commander of the Washington Navy Yard, where he established the Bureau of Ordnance. In 1863, he took command of the South Atlantic Blockading Squadron at the rank of rear admiral. He helped William Tecumseh Sherman secure Savannah, Georgia.