In the late 18th and early 19th centuries, several imperial powers including Spain, Russia, the United States and Great Britain, claimed North America’s Northwest coast. After 1824, only the United States, Russia and Britain maintained territorial claims in the region. Both Britain and the US claimed everything west of the continental divide from as far north as Russian Alaska to as far south as Mexico. This area was called the Oregon Territory by the United States and the Columbia region by the British. By 1843, increased American immigration to the Oregon Territory made the border issue a priority in Congress, where expansionists pronounced “54 degrees 40 minutes or fight.” The disputed area was the territory north and west of the Columbia River. President James Polk, a keen supporter of “Manifest Destiny”, was eager to agree the boundary of the Oregon Territory and proposed a settlement on the 49-degree line to Great Britain. The British and Americans worked out a solution that reserved the whole of Vancouver Island to Canada, and Great Britain agreed to Polk’s suggestion. The Senate ratified the treaty by a vote of 41-14 on 18 June, 1846. A later controversy over the precise boundaries in the Juan de Fuca Strait was resolved by international arbitration, which agreed the United States claim.
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