(SwStr: t. 593; l. 212'; b. 30'; dph. 9'; s. 12 k.; a. 1 3-pdr. P.r., 2 24-pdr. how.)
Isonomia, formerly Shamrock, was purchased at New York from Charles S. Leary 16 July 1864. She commissioned at New York Navy Yard 16 August, Lt. Comdr. E. Simpson In command. Isonomia sailed for Beaufort, N.C., 19 August and arrived there 23 August to join the North Atlantic Blockading Squadron. She served off New Inlet, N.C., until ordered to Key West 18 September with special instructions to cruise in the vicinity of Nassau and the Bahama Banks. But at Key West she was found unready for sea service and stationed at West Pass, Fla., where she operated until 15 November when she returned to Key West to prepare for cruising in Bahama waters. At the end of January 1865 Isonomia was returned to coastal blockade duty off western Florida and continued this duty until the end of the war. She captured British bark George Douthwaite attempting to slip into the Warrior River with a cargo of sugar, rum, wool, ginger, and mahogany from Jamaica. Towing Somerset, she sailed for New York 9 June 1865 where she decommissioned 28 June 1865 and was sold at public auction to Tabor & Co., 12 July 1865.