John A. Dahlgren

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.

Dahlgren's eldest son Charles Bunker Dahlgren (1839–1912), who had studied steam engineering, joined the U.S. Navy at the start of the Civil War and served with distinction, receiving several promotions and ending as the rank of captain. However, he declined offers to continue in federal service after the war. Among other incidents, Charles Dahlgren commanded the siege battery of 9-inch Dahlgren shell-guns which destroyed the powerful Confederate batteries at the Battle of Vicksburg, and served under his father during the blockade of Charleston.

Another of Dahlgren's sons, Colonel Ulric Dahlgren, was killed on March 2, 1864, in a cavalry raid on Richmond, Virginia, while carrying out an assassination plot against Jefferson Davis and the Confederate Cabinet. The plot became known as the Dahlgren Affair. The admiral was deeply troubled by Ulric's death and role in this event, as well as reports of the disrespectful treatment of the corpse before Richmond spymaster Elizabeth Van Lew secured its proper burial.

His brother William also spied on Confederate purchasing agents in England during the war. However, despite Radical Republican associations, John Dahlgren's younger brother Charles G. Dahlgren (1811–1888), a banker and slave owner, became a Confederate brigadier general, commander of the 3rd Brigade, Army of Mississippi, which he personally recruited and funded, until his troops' integration into the regular Confederate army and removal by Jefferson Davis in 1862.

https://en.wikipedia.org/wiki/John_A._Dahlgren