An incident that happened on June 22, 1807. The Chesapeake, a US frigate, was boarded by a British ship, the Leopard. The Chesapeake was not fully armed. The British seized four alleged deserters (the commander of the Chesapeake was later court marshaled for not taking any action). This is the most famous example of impressment, in which the British seized American sailors and forced them to serve on British ships. Impressment was one of the major factors leading to the War of 1812.