(ScGbt: t. 1,114; 1. 220'; b. 34'; dr. 16'; s. 13.5 k.; a. 1 12-pdr. r.)
The third Union—a screw steamer built at Mystic, Conn.—was chartered by the Navy on 24 April 1861 at Philadelphia, Pa.; and was commissioned there on 16 May 1861, Comdr. John R. Goldsborough in command.
The next day, Union was assigned to the Atlantic Blockading Squadron, and she steamed south to cruise off Charleston, S.C., and Savannah, Ga., on 28 May. However, she soon headed back north and captured schooner F. W. Johnson at sea off the mouth of the Chesapeake Bay on 1 June. The following morning, she arrived at Hampton Roads with the prize.
After coaling, Union returned to the blockade off Savannah and captured the brig Hallie Jackson there on the 10th. She arrived off Charleston, S.C., on the morning of the 18th and, later that day, captured the blockade runner Amelia. Union sent Amelia north to Philadelphia in the charge of a prize master and delivered the prize's crew to Fort Monroe, Va., on the 23d.
Union left Hampton Roads on 27 June to rejoin the blockade off Charleston. She sustained considerable damage to her superstructure and rigging in a collision with the Spanish ship Plus Ultra on 2 July. She was temporarily repaired at sea and sailed for Hampton Roads to refuel on 15 July. En route north, Union stopped at Georgetown, S.C.; Wilmington, N.C.; Ocra-coke Inlet, Hatteras Inlet, and Hatteras Cove in search of blockade running activity and reached her destination on 18 July.
Union was next deployed on blockade duty off Cape Hatteras. On 28 July, she found the Northern merchant brig B. T. Martin—which had been captured by Confederate privateer York—hard aground north of the cape and destroyed the prize. She briefly put into Hampton Roads for coal on 5 August, then immediately returned to blockade duty off Hatteras, where she forced the Confederate privateer York aground on the 9th. Union returned to Hampton Roads on 14 August for emergency repairs and put into Baltimore the next day for alterations.
While undergoing repairs, Union was transferred to the Potomac Flotilla on the 16th. She left Baltimore the next day and arrived in the Potomac River off Aquia Creek, Va., on 19 August. The vessel performed routine reconnaissance and dispatch duties in the Potomac and, despite heavy fire from shore, burned a large Confederate schooner in Dumfries Creek on 11 October. Union suffered no casualties during the action and received special commendation for her daring exploit from the Secretary of the Navy, Gideon Welles. The vessel remained in the Potomac until ordered north on 5 December. She was decommissioned at the Philadelphia Navy Yard on 10 December.
Union was recommissioned on 20 January 1863 and detailed to the Gulf of Mexico for use as a supply and dispatch vessel. She spent the remainder of the war operating between New York; Hampton Roads; Port Royal, S.C., and points scattered along the Florida coast and the shore of the Gulf of Mexico.
Union also compiled an impressive list of captures during this time. These included the blockade-running British schooner Linnet, captured on 21 May 1863 west of Charlotte Harbor, Fla., and the English steamer, Spaulding, taken off St. Andrew's Sound, Ga., on 11 October. On 14 January 1864, Union seized steamer Mayflower and her cargo of cotton near Tampa Bay, Fla.; and, on 26 April, she captured schooner O.K. south of the bay. The supply vessel's final prize was sloop Caroline, captured at Jupiter Inlet, Fla., on 10 June 1864.
Union completed several dispatch and supply missions after the war ended and was decommissioned at New York on 29 September 1865. She was sold at auction there to W. H. Starbuck on 25 October and was re-documented as Missouri on 8 December. The steamer remained in merchant service until she caught fire and sank in the Bahamas on 22 October 1872, some 25 miles northeast of Abaco. This disaster cost the lives of some 69 persons.