Rear Admiral John Adolph Dahlgren, U.S.N., (1809-1870), son of the Swedish Consul in Philadelphia, Pennsylvania, made his career in the United States Navy. He headed the Union Navy's ordnance department during the American Civil War and designed several different kinds of guns and cannons that were considered part of the reason the Union won that war. The Naval station in Dahlgren, Virginia, and Dahlgren Hall at the U.S. Naval Academy in Annapolis, Maryland, were named for him, and so was Dahlgren, Illinois.
See also: John Ericsson