What country forms the northern border of the US?

Answer 1

Rio Grande forms the Southern border of the United states.

Answer 2

No one state forms the "most" northern border. "Most" implies the majority of something, or more than half. Michigan has the longest border with Canada of the Contiguous US: 720 miles or about 19% of the Contiguous US border with Canada.

Keep in mind that this border with Canada is not 100% Michigan's northern border. If one travels due south from Detroit, they end up in Canada before they would get to Ohio.

For reference, Alaska has a 1500+ mile eastern border with Canada.

Maine (611 miles), Minnesota (547 miles) and Montana (545 Miles) round out the top 5 in length of Canadian border.

Answer 3

Canada forms most of the northern border of the United States.

Answer 4

Canada is the northern border for the upper 48 states.

Answer 5

Canada forms most of the northern border of the United States.
Canada forms most of the northern border of USA.

Answer 6

Mongolia forms most of china's northern border

Answer 7

Canada forms the entire northern border of the "lower 48" states either through land or water.

Answer 8

Canada forms most of the northern border of USA.

Answer 9

Canada
Canada.

Answer 10

Canada.