On June 10, 1805, a peace treaty between Yussif Karamanli and the United States ended hostilites in the First Barbary War.

The First Barbary War, which lasted from 1801 to 1805, was the first of two wars fought between the United States and the North African states known collectively as the Barbary States. This included Morocco, Algiers, Tunis, and Tripoli. Morocco was independent, but Algiers, Tunis, and Tripoli were quasi-independent members of the Ottoman Empire.

Barbary pirates were a growing problem in the Mediterranean in the late 1700s. Britain and France were generally protected from the pirates due to their military might and ability to pay off the pirates in advance. The United States, as a British colony, was protected from the Barbary pirates until the American Revolution. After that, American ships were protected by France due to a 1778 treaty between the countries. However, in 1783, America became responsible for its own protection in the Mediterranean waters.

Without the military means or the authority to field a navy necessary to protect their ships in the Mediterranean, the U.S. government attempted to pay off the Barbary pirates and negotiate a peace treaty. Though it would put the United States even deeper in debt (after the already draining Revolutionary War) the government agreed to pay the Barbary nations in exchange for safe passage.

Thomas Jefferson, who was the United States Ambassador to France at the time, strongly believed that paying the Barbary states would be a slippery slope, with their demands for money growing larger every year. When he was elected President in 1800, Yussif Karamanli, the leader of Tripoli, demanded $225,000 from the new administration. Jefferson refused, and the Barbary states declared war on America.

The fighting lasted until 1805, when the United States was in position to invade Tripoli. Weary of the blockade and raids, Yussif Karamanli signed a treaty ending hostilities on June 10, 1805.