USA HISTORY

Detailed explanation-1: -In 1818, a U.S.-British agreement had established the border along the 49th parallel from Lake of the Woods in the east to the Rocky Mountains in the west.

Detailed explanation-2: -The United States and Great Britain signed the Treaty of Oregon on June 15, 1846, ending 28 years of joint occupancy of the Pacific Northwest. The treaty established the 49th parallel as the border between the two countries.

Detailed explanation-3: -The 49th parallel north as a border between the Canadian provinces of British Columbia, Alberta, Saskatchewan and Manitoba (to the north), and the U.S. states of Washington, Idaho, Montana, North Dakota and Minnesota (to the south).

Detailed explanation-4: -The 49th parallel has since become synonymous with the Canadian border as a whole, as a shorthand for that larger political divide between the Manifest Destiny to the south and the muddled patchwork to the north. Between melting pot and mosaic, as it were.