 U.S. Route 1 was built at the time to be the north-south highway on the Atlantic coast of the U.S., and it remains the longest north-south highway in the country, stretching 2,370 miles. Route 1 goes from the town of Kent in Maine on the Canadian border all the way south to Miami. And while today you would drive from Maine to Florida using I-95, you could, in theory, still make that trip exclusively on Route 1.