The Tripolitan War (1801-1805) was a conflict between the United States and the North African state of Tripoli. It arose after Tripoli demanded increased tribute payments from American merchant ships, which the U.S. refused to pay. This led to the capture of American vessels and crews, prompting President Thomas Jefferson to take military action. The war involved naval battles and the use of Marines, notably the famous raid on Derna. The conflict ended with a treaty in 1805, which reduced tribute payments and secured the release of American prisoners. This war marked the beginning of U.S. military engagement in the Mediterranean.