The main cause of the War of 1812 was the ongoing tensions between the United States and Great Britain, primarily related to issues of trade restrictions, impressment of American sailors, and British support for Native American resistance against American expansion. The British imposed trade restrictions to weaken the American economy and forcibly recruited U.S. sailors into their navy, infuriating the American public. The conflict also had underlying causes tied to national pride and territorial ambitions. These provocations culminated in a declaration of war by the United States in June 1812, marking the onset of a tumultuous conflict that would last until 1815.