No longer covered by British tribute payments after the American Revolution, United States merchant ships were seized and sailors enslaved in the years that followed independence. In 1794 the United States Congress appropriated funds for the construction of warships to counter the privateering threat in the Mediterranean. Despite the naval preparations, the United States concluded a treaty with the dey of Algiers in 1797, guaranteeing payment of tribute amounting to US$10 million over a twelve-year period in return for a promise that Algerian corsairs would not molest United States shipping.