John Adolphus Dahlgren, born 13 November 1809 in Philadelphia, Pa., was appointed a midshipman 1 February 1826, and early became interested in the problems of ordnance. He developed the famous Dahlgren gun, perfected howitzers for use afloat and ashore, organized the Naval Gun Factory, and wrote several significant books on ordnance. From the outbreak of the Civil War until July 1862 he served as Commandant of the Washington Navy Yard where President Lincoln often conferred with him. He then became Chief of the Bureau of Ordinance and on 7 February 1863 was promoted to the rank of Rear Admiral. In command of the South Atlantic Blockading Squadron (7 July 1863-17 June 1866), he participated in the bombardment of Fort Wagner and cooperated with Sherman in the capture of Savannah and Charleston. After a tour of duty in command of the South Pacific Squadron (1866 1868), he returned to Washington again as Chief of the Bureau of Ordnance. Rear Admiral Dahlgren resigned this job a year later to return to the command of the Navy Yard and Gun Factory. He died in Washington 12 July 1870.

(TB-9: dp. 146; l. 161'4"; b. 16'4"; dr. 4'8"; s. 80 k.; cpl. 29; a. 4 1-pdr., 2 18" tt.)

Dahlgren, torpedo boat No. 9, was launched 29 May 1899 by Bath Iron Works, Bath, Maine; sponsored b, Mrs J. V. Dahlgren, daughter-in-law of Rear Admiral Dahlgren; and commissioned 19 June 1900, Lieutenant M. H. Signor in command.

Assigned to the Atlantic Torpedo Fleet, Dahlgren operated out of Portsmouth, N.H., and Newport, R.I., developing tactics for her new type of ship and training crews until 20 October 1900 when she returned to Portsmouth and was placed out of commission for repairs and alterations.

In partial commission from 7 June 1902, she sailed to Newport 13 June for an overhaul until 18 November 1902. The next day she was placed in full commission and reported to New Suffolk, L.I., to assume duty as a station ship until 28 October 1903. She again went out of commission 22 December 1903 at New York Navy Yard.

Assigned to the Naval Training Stations at Newport and New York during 1906, Dahlgren was placed in reduced commission 13 December 1906 and reported to the Reserve Torpedo Flotilla at Norfolk. Changing her base to Charleston, S.C., 16 October 1908, she continued to serve in torpedo developmental operations until placed in ordinary 14 March 1914.

After being fitted for minesweeping, Dahlgren was placed in full commission 1 April 1917 and served on escort and harbor entrance patrol at Norfolk until 6 December 1917. Renamed Coast Torpedo Boat No. 4, 1 August 1918, she arrived at Philadelphia Navy Yard from Norfolk 27 January 1918, and there was placed out of commission 11 March 1919. She was sold 19 July 1920.