Template:POTD/2021-11-13
John A. Dahlgren (November 13, 1809 – July 12, 1870) was a United States Navy officer who founded the Navy's Ordnance Department and launched major advances in gunnery. He introduced a cast-iron muzzle-loading cannon with vastly increased range and accuracy, known as the Dahlgren gun, which became the Navy's standard armament. During the American Civil War, he was made the commander of the Washington Navy Yard. He also served at sea, being put in command of the South Atlantic Blockading Squadron.Photograph credit: Mathew Brady; restored by Jebulon