The Cumberland Road, also known as the National Road or National Turnpike, was the first road in the history of the United States funded by the federal government. President Thomas Jefferson promoted the road to support westward expansion and unify the developing nation, and Congress authorized its construction in 1806.

By the middle of the century, the United States' first national highway ran from Cumberland, Maryland, to St. Louis, Missouri. It fulfilled Jefferson’s promise to unify the country: It promoted commerce and encouraged travel between the Atlantic colonies and the West. It also laid the foundation for the U.S. federal highway system.

The construction of a federal road sparked controversy at the time Congress approved it, however. Many statesmen could not justify the expense, given the fact that, by this time, canals and rivers had proven to be efficient for transport. More significantly, however, people questioned the idea that the federal government should fund a roadway. They questioned whether the Constitution allowed for it. Today, federal highways form the backbone of the country’s infrastructure. In the early 1800s, however, most passageways were funded by the states that housed them and that benefited from their construction. The Erie Canal was an early exception; it was funded by the state of New York despite the fact that it benefited other states.

Nevertheless, in 1811, construction of the Cumberland Road began, running through Maryland and West Virginia. The road was built in sections over a series of decades, and became something of a bustling highway. It spawned the development of towns, villages, and roadside establishments. It also provided a model for urban planning and commercial development as roadways became an integral part of the U.S. landscape.

The fits and starts that characterized the nation’s first federal road continued throughout its existence, and its popularity at different times reflected the social environment of the country. The popularity of the National Road soared in the 1840s when it became a popular route for Conestoga wagons that encouraged a thriving commercial trade. In the 1870s, with the rise in railroads, the National Road lost its appeal, but by the 1920s it had made a comeback. The development of the automobile revived interest in the road, and federal funds increased to support the growth of the federal roadway system. The interstate highway system grew. The Cumberland Road, once dubbed “the Main Street of America,” became known as “the road that built a nation.” To support the need for improved roads, in 1926, the Cumberland Road was incorporated into Interstate 40, which runs coast to coast.