The Lincoln Highway is one of the first transcontinental highways in the United States and one of the first highways designed expressly for automobiles. Conceived in 1912 by Indiana entrepreneur Carl G. Fisher, and formally dedicated October 31, 1913, the Lincoln Highway runs coast-to-coast from Times Square in New York City west to Lincoln Park in San Francisco. The full route originally ran through 13 states: New York, New Jersey, Pennsylvania, Ohio, Indiana, Illinois, Iowa, Nebraska, Colorado, Wyoming, Utah, Nevada, and California. In 1915, the "Colorado Loop" was removed, and in 1928, a realignment routed the Lincoln Highway through the northern tip of West Virginia. Thus, there are 14 states, 128 counties, and more than 700 cities, towns, and villages through which the highway passed at some time in its history.

The first officially recorded length of the entire Lincoln Highway in 1913 was 3,389 miles (5,454 km). Over the years, the road was improved and numerous realignments were made, and by 1924 the highway had been shortened to 3,142 miles (5,057 km). Counting the original route and all of the subsequent realignments, there has been a grand total of 5,872 miles (9,450 km).

The Lincoln Highway was gradually replaced with numbered designations after the establishment of the U.S. Numbered Highway System in 1926, with most of the route becoming U.S. Route 30 from Pennsylvania to Wyoming. After the Interstate Highway System was formed in the 1950s, the former alignments of the Lincoln Highway were largely superseded by Interstate 80 as the primary coast-to-coast route from the New York City area to San Francisco.

Most of U.S. Route 30 from Philadelphia to western Wyoming, portions of Interstate 80 in the western United States, most of U.S. Route 50 in Nevada and California, and most of old decommissioned U.S. Route 40 in California are alignments of the Lincoln Highway. The final (1928–1930) alignment of the Lincoln Highway corresponds roughly to the following roads:

The Lincoln Highway was the first national memorial to President Abraham Lincoln in the United States, predating the 1922 dedication of the Lincoln Memorial in Washington, D.C. by nine years. As the first automobile road across the United States, the Lincoln Highway brought great prosperity to the hundreds of cities, towns and villages along the way. The Lincoln Highway became affectionately known as "The Main Street Across America".

The Lincoln Highway was inspired by the Good Roads Movement and the National Old Trails Road. In turn, the success of the Lincoln Highway and the resulting economic boost to the governments, businesses and citizens along its route inspired the creation of many other named long-distance roads (known as National Auto Trails), such as the Yellowstone Trail, Dixie Highway, Jefferson Highway, Bankhead Highway, Jackson Highway, Meridian Highway and Victory Highway. Many of these named highways were supplanted by the United States Numbered Highways system of 1926. Most of the 1928 Lincoln Highway route became U.S. Route 30 (US 30), with portions becoming US 1 in the East and US 40, US 50 and US 93 in the West.

Most significantly, the Lincoln Highway inspired the Federal Aid Highway Act of 1956, also known as the National Interstate and Defense Highways Act (Public Law 84-627), which was championed by President Dwight D. Eisenhower, influenced by his experiences as a young soldier crossing the country in the 1919 Army Convoy on the Lincoln Highway. Today, Interstate 80 (I-80) is the cross-country highway most closely aligned with the Lincoln Highway. In the West, particularly in Wyoming, Utah and California, sections of I-80 are paved directly over old alignments of the Lincoln Highway.

The Lincoln Highway Association, originally established in 1913 to plan, promote, and sign the highway, was re-formed in 1992 and is now dedicated to promoting and preserving the road.