As Great Britain and her American colonies drifted into open conflict during 1775, the foundations of the United States' Navy were laid that December when the new Continental Congress took the decision to build thirteen frigates. On 20th November the next year, by which time the War of American Independence had begun in earnest, a second Act of Congress authorised ten further warships, including five additional frigates, one of which was to be named Confederacy.

Built in 1778 by Jedediah Willets on the Thames River at Norwich, Connecticut, the Confederacy was measured at 971 tons and was 154½ feet in length (berth deck) with a 37 foot beam, a highly unusual ratio by the standards of the time. Nominally a fifth rate mounting 36 guns, she was exceptionally long, almost 160 feet overall, and bore a marked resemblance to the so-called "galley-frigates" of the previous century. Built and rigged for speed yet strikingly ornate, with profuse carving, another of her innovative features was a speaking tube just abaft her wheel on the quarterdeck. This led to the berth deck immediately below and was intended to be used to direct the men who would have to steer her by means of the heavy tiller and its ropes in the event that the quarter deck wheel was shot away. It has been suggested (see The History of the American Sailing Navy, Howard Chapelle, 1948) that Confederacy's lines may have represented the official design for her class but whether this is true or not, she was described as being "a very fast ship and well built" at the time of her subsequent capture by the Royal Navy.

Despite her many merits, she proved an unlucky ship and saw little service under the Continental flag after her early success on 6th June 1779 when, in company with the U.S. frigate Boston, she captured three English privateers. Her next mission was to carry a French diplomat back to Europe but when, after many delays, she was finally able to sail towards the end of the year, she was severely damaged in a gale off the Bahamas and had to put into Martinique to be re-rigged. Eventually returning to the safety of the Delaware, she was then found to be in need of an extensive refit which took most of 1780 to complete. Returning to service, she captured two British merchantmen, the Elizabeth and the Nancy, in the Atlantic on 5th January 1781 but was then herself taken off the Virginia Capes on 14th April. She was returning home from Cape François (Martinique) loaded with valuable military stores and colonial produce when she was sighted by two British frigates, H.M. Ships Roebuck and Orpheus, patrolling the eastern seaboard. They gave chase and, without a shot being fired, forced Confederacy to surrender whereupon she was absorbed into the Royal Navy with her name slightly amended to Confederate.

Notwithstanding her obvious usefulness as a reinforcement to the British naval presence off North America, there is no record of Confederate being in action again as the War entered its final phase. Given how new she was and the fact that she was the largest 36-gun ship in the fleet, it is even more surprising that she is then recorded as being broken up in 1782, even before hostilities had been formally concluded. Perhaps the 1779 storm off the Bahamas had fundamentally weakened her but, whatever the reason, it was a sadly premature end to a remarkable vessel which had been much admired during her short life.