THE HISTORY OF US 1, which runs from the Canadian Boundary of Maine to southern Florida, reflects the history of the Atlantic Seaboard States. North of Baltimore the route approximates the Old Post Road, first official intercolonial highway of the country connecting the leading cities of all the thirteen Colonies but Delaware. The cities of this northern section maintained their primacy as settlement spread inland. South of Baltimore, however, the early commercial and cultural centers along the coast gradually lost leadership to cities that developed inland along the geologic fall line; the main northand-south highway connecting the States veered inland with the shift of power. It is significant that when Federal highway numbering began in 1925 this old route became US 1. It remains as it was in Colonial and early Federal days the chief line of communication between the centers of the Atlantic Seaboard States.
With increasing congestion of metropolitan areas, US 1 has in many places been rerouted to bypass the centers of the cities it formerly traversed. It still, however, runs through country intimately bound up with important events. In Maine the route runs close to the sites of the first two settlements attempted in New England; in Florida it passes through St. Augustine, the oldest settlement in the present United States. Many of the New England towns through which it runs were "little hornets' nests" during the Revolutionary War. Over a part of the route Paul Revere in 1773 spurred his horse on his dash to Philadelphia with news of the Boston Tea Party. Fort Washington in New York City is where three thousand Americans surrendered to General Howe in 1776, completing the abandonment of the city. Across the river in New Jersey the route passes the site of old Fort Lee, from which Washington watched the attack and surrender of his Fort Washington garrison. Lafayette and his troops in 1781 hurried along this road to oppose the British invasion of Richmond.
This highway was likewise closely bound up with the Civil War. In Pennsylvania US 1 traverses the territory in which first rose the opposition to the institution of slavery that was to culminate in the bitterest internal struggle of the nation. The highway crosses the MasonDixon line, which marked the division between the free and slave States in this war. In Virginia it runs close to the bloody battlefield from which in 1864 Grant sent the words that became the slogan of