query: How long is the Canadian-U.S. border?
passage: Canada–United States border
The Canada–United States border (French: frontière Canada–États-Unis), officially known as the International Boundary (French: Frontière Internationale), is the longest international border in the world between two countries. It is shared between Canada and the United States, the second- and fourth-largest countries by area, respectively. The terrestrial boundary (including portions of maritime boundaries in the Great Lakes, and on the Atlantic, Pacific, and Arctic coasts) is 8,891 kilometres (5,525mi) long, of which 2,475 kilometres (1,538mi) is Canada's border with Alaska. Eight Canadian provinces and territories (Yukon, British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec, and New Brunswick), and thirteen U.S. states (Alaska, Washington, Idaho, Montana, North Dakota, Minnesota, Michigan, Ohio, Pennsylvania, New York, Vermont, New Hampshire, and Maine) are located along the border.
passage: Mexico–United States border
Data from the United States Border Patrol Agency's (USBP) 2010 annual report shows that among the total number of border crossings without documentation from various countries into the United States, 90 percent were from Mexico alone. In addition, there are more than 6 million undocumented Mexican nationals residing in the United States.[33] The border, with a length of 3,145 kilometers (1,954mi), has a very high rate of documented and undocumented migrant crossings every year. With such a high rate of people crossing annually to the United States, the country has invested in several distinct security measures.