The Canada–United States border is the world’s longest international boundary. The boundary stretches for 5,525 miles (8,891 km) from the Atlantic Ocean in the east to the Pacific Ocean to the west. It cuts across lakes, forests, glaciers, and towns. Eight Canadian provinces share the boundary with thirteen American states. A six feet “no-touching-zone” is maintained along the borderline unless in unavoidable circumstances.
Forming the Boundary
The boundary was established on September 3, 1783, by the Treaty of Paris after the end of the American War of Independence. After the signing of the treaty, the United States and Canada differed on the demarcation of several locations and almost engaged in armed conflicts. Several treaties including the Jay Treaty, the Treaty of 1818, the Webster–Ashburton Treaty, and the Oregon Treaty were agreed upon to solve boundary disputes. The current shape of the boundary lines came into being when the Treaty of 1908 was signed.
The boundary was meant to be demarcated by the 49th parallel, but several factors prevented a straight line from Maine to Washington State. The Great Lakes, for example, had to be shared by both countries, a phenomenon that forced the boundary to curve southwards in into northern Ohio. The boundary from the northeast corner of Minnesota to the northwest corner of Washington State is not as straight as it looks on the map although it was meant to be. The pre-GPS technology of the early 20th century could not allow the surveyors to establish a straight line, so they instead established a zigzagging line.
States on the Border
The thirteen American states found along the Canada-US border, from west to east, are Alaska, Washington, Idaho, Montana, North Dakota, Minnesota, Michigan, Ohio, Pennsylvania, New York, Vermont, New Hampshire, and Maine.
Alaska shares the longest border with Canada of any state. The 1,538-miles (2,475 km) long border is shared with Yukon and British Columbia. Alaska was purchased by the United States from Russia in 1867. The borderline was demarcated in 1903 when the United Kingdom and the United States signed an agreement. The agreement favored the United States and did not settle well with the Canadians who felt betrayed by the United Kingdom for preventing a direct outlet from Yukon to the sea. There are five border crossings, two of which connect Alaska to the Yukon and three that connect Alaska to British Columbia.
The entire northern boundary of Washington State borders British Columbia. The border is 427 miles (687 km) long. It is a relatively straight boundary demarcated along the 49th parallel. The borderline curved around Vancouver Island to avoid separating the people who were already living on it. There are 13 drivable border crossings; four of the busiest connect Seattle to Vancouver.
Idaho shares a 45-mile (72 km) long boundary with British Columbia. The boundary is located north of Idaho’s narrow strip between Washington state and Montana. There are only two border crossing points within the boundary: Porthill which is commonly used by passenger vehicles, and Eastport which is preferred by trucks.
Montana is the only American state that borders more than two Canadian provinces. The state borders British Columbia to the northwest, and Alberta and Saskatchewan to the north. The entire boundary covers 545 miles (877 km). Four airports run across the international boundary between Canada and Montana.
9. North Dakota
North Dakota shares a 310-mile (499 km) long boundary with Saskatchewan and Manitoba to the north. The borderline is fairly straight and contains 18 international border crossings. Portal, Pembina, Neche, and Peace Garden are the four busiest crossings. The International Peace Garden Airport cuts across the national boundary.
The US state of Minnesota shares a 547-mile (880 km) long border with Canadian provinces of Manitoba and Ontario. Manitoba is located on the northwest corner of Minnesota while Ontario lies on the north and northeast. Part of the border with Ontario runs along Lake Superior.
Michigan and Ontario share a 721-mile (1,160 km) marine boundary. It is the second longest boundary between the two countries. There is no land border between Michigan and Canada. The borderline runs along Lake Superior and Lake Huron, demarcating the lakes’ share owned by both countries. The Blue Water Bridge and St. Clair Tunnel connects Sarnia in Ontario to Port Huron in Michigan. The Ambassador Bridge and the Windsor-Detroit Tunnel connect Windsor, Canada and Detroit, USA.
Ohio shares a 146-mile (235 km) long boundary with Ontario. The borderline is located entirely within Lake Erie. The only form of transport between the two territories is by ferry across the lake. The Pelee Island Ferry operates between Sandusky in Ohio and Essex County in Ontario.
Pennsylvania has the shortest border with Canada. The maritime boundary shared with Ontario stretches for 42 miles (68 km) within Lake Erie and demarcates the lake share owned by both countries. Pennsylvania has no land boundary with Canada.
4. New York
New York State shares a 445-mile (716 km) long boundary with Ontario and Quebec. The Treaty of Paris established the boundary in 1783 while the Webster–Ashburton Treaty 1842 revised the borderline. The St Lawrence rivers forms part of the boundary between New York and Ontario. The boundary has four of the most-used border crossing between Canada and the United States.
Vermont and Quebec share a 90 mile (145 km) long boundary. The Treaty of Paris established the boundary, but the Webster–Ashburton Treaty redefined it. The are 15 border crossing points including Highgate Springs–Saint-Amand/Pillsburg and Derby Line–Stanstead, both of which are majorly used by trucks.
2. New Hampshire
New Hampshire shares a 58 mile (93 km) long border with Quebec. However, there is only one border crossing located at the terminals of the U.S. Route 3 in the town of Pittsburgh. Pittsburgh is geographically extensive but has fewer than 1,000 residents.
The US state of Maine shares a 611-mile (983 km) long border with Quebec and New Brunswick, the third longest state boundary with Canada. Between 1838 and 1839, Maine and New Brunswick engaged in territorial disputes over the boundary. In 1842, the United Kingdom and the United States signed in the Webster–Ashburton Treaty that formally ended the dispute. The Aroostook Valley Country Club is located along the border and extends to both countries. There are 24 land border-crossing points connecting Maine to Canada.