During King George's War, approximately 36,000 Americans served aboard privateers at one time or another. During the American Revolution, about 55,000 American seamen served aboard the privateers. The American privateers had almost 1,700 ships, and they captured 2,283 enemy ships. Between the end of the Revolutionary War and 1812, less than 30 years, Britain, France, Naples, the Barbary States, Spain, and the Netherlands seized approximately 2,500 American ships. Payments in ransom and tribute to the Barbary states amounted to 20% of United States government annual revenues in 1800. Throughout the American Civil War, Confederate privateers successfully harassed Union merchant ships.