USS Union ( 1861 ) The third USS " Union " was a heavy ( 1 , 114 - ton ) steamer with a powerful 12 - inch rifled gun purchased by the United States Navy during the American Civil War . " Union " served the U . S . Navy successfully during the blockade of ports and waterways of the Confederate States of America , capturing numerous blockade runner s . Towards wars end , she was also assigned the role of dispatch boat and , because of her large size , of storeship , at the same time continuing to capture blockade runners . Commissioned in Philadelphia in 1861 . " Union " , a screw steamer built at Mystic , Connecticut , was chartered by the U . S . Navy on 24 April 1861 at Philadelphia , Pennsylvania , and was commissioned there on 16 May 1861 with Commander John R . Goldsborough in command . Civil War service . Assigned to the Atlantic Blockade . The next day , " Union " was assigned to the Atlantic Blockading Squadron , and she steamed south to cruise off Charleston , South Carolina , and Savannah , Georgia , on 28 May 1861 . However , she soon headed back north and captured the schooner " F . W . Johnson " at sea off the mouth of the Chesapeake Bay on 1 June 1861 . The following morning , she arrived at Hampton Roads , Virginia , with the prize . After coaling , " Union " returned to the blockade off Savannah and captured the brig " Hallie Jackson " there on 10 June 1861 . She arrived off Charleston on the morning of 18 June 1861 and , later that day , captured the Confederate blockade runner " Amelia " . " Union " sent " Amelia " north to Philadelphia in the charge of a prize master and delivered the " Amelia " s crew to Fort Monroe , Virginia , on 23 June 1861 . Collision with blockade runner . " Union " left Hampton Roads on 27 June 1861 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 1861 . She was temporarily repaired at sea and sailed for Hampton Roads to refuel on 15 July . En route north , " Union " stopped at Georgetown , South Carolina ; Wilmington , North Carolina ; Ocracoke Inlet ; Hatteras Inlet ; and Hatteras Cove in search of blockade runners and reached her destination on 18 July 1861 . " Union " was next deployed on blockade duty off Cape Hatteras . On 28 July 1861 , she found the Union merchant brig " B . T . Martin " — which had been captured by Confederate privateer " York " — hard aground north of the cape and destroyed her . " Union " briefly put into Hampton Roads for coal on 5 August 1861 , then immediately returned to blockade duty off Cape Hatteras , where she forced " York " aground on 9 August 1861 . " Union " returned to Hampton Roads on 14 August 1861 for emergency repairs and put into Baltimore , Maryland , the next day for alterations . Transferred to the Potomac flotilla . While undergoing repairs , " Union " was transferred to the Potomac Flotilla on 16 August 1861 . She left Baltimore the next day and arrived in the Potomac River off Aquia Creek , Virginia , on 19 August 1861 . She performed routine reconnaissance and dispatch duties on the Potomac River and , despite heavy fire from shore , burned a large Confederate schooner in Dumfries Creek on 11 October 1861 . " Union " suffered no casualties during the action and received special commendation for her daring exploit from the United States Secretary of the Navy , Gideon Welles . The vessel remained on the Potomac until ordered north on 5 December 1861 . She was decommissioned at the Philadelphia Navy Yard in Philadelphia on 10 December 1861 . Recommissioned as a supply and dispatch vessel . " Union " was recommissioned on 20 January 1863 and detailed to the Gulf of Mexico for use as a storeship and dispatch vessel . She spent the remainder of the war operating between New York City ; Hampton Roads ; Port Royal , South Carolina ; 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 , Florida , and the British steamer " Spaulding " , taken off St . Andrew ' s Sound , Georgia , on 11 October 1863 . On 14 January 1864 , " Union " seized the steamer " Mayflower " and her cargo of cotton near Tampa Bay , Florida , and , on 26 April 1864 , she captured the schooner " O . K . " south of the bay . " Union " s final prize was the sloop " Caroline " , captured at Jupiter Inlet , Florida , on 10 June 1864 . Post - war sale and subsequent career . " Union " completed several dispatch and supply missions after the American Civil War ended and was decommissioned at New York City on 29 September 1865 . She was sold at auction there to W . H . Starbuck on 25 October 1865 and was re - documented as S . S . " Missouri " on 8 December 1865 . As " Missouri " , she remained in merchant service until she caught fire and sank in the Bahamas on 22 October 1872 , some 25 nautical miles ( 29 statute miles ; 46 km ) northeast of Abaco , costing the lives of some 69 persons .