dal'gren, (1809-1870), an American naval officer and artillerist. He entered the navy in 1826 and afterward served in the coast survey. In 1850 he brought forward his invention of the gun which was named for him, which was of great value during the war. Subsequently he cruised in the West Indies, and on his return to Washington he resumed command of the ordnance department, of which he was made chief in 1862. At the beginning of the Civil War he became commandant of the Washington navy yard, and in 1863 he was made rear admiral, and was placed in command of the South Atlantic blockading squadron. In 1866 he had command of the South Pacific squadron, and in 1868 he again took charge of the bureau of ordnance in Washington. In the following year he was appointed commandant of the Washington navy yard.