She was launched on 8 November 1778 at Chatham (Norwich), Connecticut, and towed to New London to be prepared for sea. From 1 May to 24 August 1779 she cruised on the Atlantic coast under the command of Captain Seth Harding. While convoying a fleet of merchantmen, on 6 June, she and captured three prizes, drove off two British frigates and brought the convoy safely into Philadelphia, Pennsylvania.
On 17 September 1779 Confederacy was ordered to carry the French Minister and his family back to France. Later John Jay, the first American Minister to Spain, his secretary, and family were added to the passenger list. During the passage on 7 November 1779 Confederacy was completely dismasted and almost lost, but managed through the skillful seamanship of Captain Harding to reach Martinique early in December. After repairs, she returned to convoy duty.
Captain Nicholson replaced Harding in on 20 October 1780.
Confederacy was homeward bound from Cape Francois in the West Indies in 1781 with military stores and other supplies and escorting a fleet of 37 merchantmen, when on 14 April she encountered (44) and (32) off the Delaware Capes. The British ships forced Confederacy to strike her flag. Most of the merchantmen she was escorting escaped. Many of her crew were sent to the old prison hulk, though some ended up in Mill and Forton prisons.
The Royal Navy sent her to England, under the command of Captain James Cumming. He paid her off in September 1781. She was never commissioned and was docked on 18 November 1781 at Woolwich. She was broken up there in March 1782.[1]