How did British impressment of sailors anger the United States?

The British practice of impressment—the forced recruitment of men into naval service—deeply angered the United States because the Royal Navy frequently halted American merchant vessels to search for deserters. During these encounters, British forces often seized naturalized American citizens, carrying off thousands of U.S. sailors into their own navy.12

This violation of sovereignty and personal liberty was a major grievance that contributed to the War of 1812. Tensions reached a breaking point in 1807 when the British frigate H.M.S. Leopard fired upon the U.S. Navy frigate Chesapeake, seizing four sailors, three of whom were U.S. citizens. While Britain eventually apologized for this specific incident, the policy of impressment remained in place, fueling American resentment and the conviction that the United States was being treated with a lack of honor and respect. For many Americans, the defense of "free trade and sailors' rights" became a central rallying cry for war.12