Canada and the United States of America share the longest common border among any two countries that is not militarized or actively patrolled. The terrestrial boundary (including small portions of maritime boundaries on the Atlantic, Pacific and Arctic coasts as well as the Great Lakes) is 8,891 km long, including 2,477 km shared with Alaska.

History

Officially known as the International Boundary, the present border originated with the Treaty of Paris in 1783, which ended the war between Great Britain and the separating colonies which would form the United States. The Jay Treaty of 1794 created the International Boundary Commission, which was charged with surveying and mapping the boundary. Disputes over the interpretation of boundary demarcation led to the Aroostook War and the ensuing Webster–Ashburton Treaty in 1842 which better defined the boundary between Maine and New Brunswick and the Province of Canada. Westward expansion of both British North America and the United States saw the boundary extended west from the Lake of the Woods to the Rocky Mountains under the Convention of 1818. U.S. President James Knox Polk's expansionist desires for the northern boundary of the U.S. to be 54°40′ north (related to the southern boundary of Russia's Alaska Territory), and Great Britain's claim that the border should follow the Columbia River to the Pacific Ocean, led to the Oregon Treaty in 1846, which established the 49th parallel as the boundary through the Rockies. In 1903 a joint Great Britain–Canada–U.S. tribunal established the boundary with Alaska. In 1925 the International Boundary Commission was made a permanent organization responsible for surveying and mapping the boundary, maintaining boundary monuments (and buoys where applicable), as well as keeping the boundary clear of brush and vegetation for 6 metres (20 feet) on each side of the line.

Security

Commonly referred to as the world's longest undefended border, the International Boundary is actually defended, but by law enforcement and not military personnel. The relatively low level of security measures stands in stark contrast to that of the Mexico-U.S. border (1/3 as long as the Canada-U.S. border), which is actively patrolled by U.S. customs and immigration personnel to prevent Mexican citizens from illegally entering the United States (see United States Mexico barrier).

It should be noted that since the September 11, 2001 terrorist attacks in the United States, border security along the International Boundary has been dramatically (and often covertly) improved by both nations in both populated and rural areas alike. Both nations are also actively involved in detailed and extensive tactical and strategic intelligence sharing.

American and Canadian citizens owning property adjacent to the border are required to report construction of any physical border crossing on their land to their respective governments, and this is enforced by the International Boundary Commission. Where required, fences or vehicle blockades are used. All persons crossing the border are required to report to the respective customs and immigration agencies in each country. In remote areas where staffed border crossings are not available, there are hidden sensors on roads and also scattered in wooded areas near crossing points and on many trails and railways, but there are not enough border personnel on either side to verify and stop coordinated incursions.

Parts of the International Boundary cross through mountainous terrain or heavily forested areas, but significant portions also cross remote prairie farmland and the Great Lakes and Saint Lawrence River, in addition to the maritime components of the boundary at the Atlantic, Pacific, and Arctic oceans. The actual number of U.S. and Canadian border security personnel is not known but estimated to be less than 1,000 in total, largely clustered near major crossing points. In comparison, there are in excess of 7,000 U.S. border security personnel on the Mexico-U.S. border alone.

In past years Canadian officials have complained of cigarette and firearms smuggling from the United States while U.S. officials have complained of drug smuggling from Canada. Human smuggling into both countries, but primarily from Canada into the U.S., has been an ongoing problem for border security and law enforcement personnel.

Remaining boundary disputes

• Machias Seal Island (Maine/New Brunswick)
• Strait of Juan de Fuca (Washington/British Columbia)
• Dixon Entrance (Alaska/British Columbia)
• Beaufort Sea (Alaska/Yukon)

Other border crossings (airports, seaports)

The U.S. maintains immigration offices, called "pre-clearance facilities," in all Canadian airports with international air service. This expedites travel by allowing flights originating in Canada to land at a U.S. airport without being processed as an international arrival. Similar arrangements exist at major Canadian seaports which handle sealed direct import shipments into the United States. Canada also maintains equivalent personnel at selected U.S. airports and seaports.

Several ocean-based ferry services operate between the provinces of New Brunswick and Nova Scotia to the state of Maine, as well as between the province of British Columbia and the state of Washington. There are also several ferry services in the Great Lakes operating between the province of Ontario and the states of Michigan, New York, and Ohio.

External links

• International Boundary Commission