He sailed, 4 August, 1782, on the most successful cruise of the war; the prizes he captured sold for £600,000. Returning by way of West Indies and Havana, on 10 March 1783, he fell in with the British frigate "Sybille", 38 guns, and after a sharp fight of 45 minutes she hauled off apparently much injured and joined two other ships with which she had been in company. This was the last encounter of the Revolutionary war at sea.
Joint Resolution 98, 105th Congress, 1st Session, 28 Oct 1997: "Whereas Captain John Barry, in command of the frigate Alliance, having successfully transported French gold to America to finance the War for Independence, also won the last sea battle of that war against the HMS Sybille on March 10, 1783"
"Naval Battles 1776-1800", map. This map shows the engagement off FL, which is reasonable with it occurring several days after Barry left Havana, and following a chase. Basis for site selection.