On June 29, 1956, President Dwight D. Eisenhower signed the Federal-Aid Highway Act of 1956 into law, creating the United States Interstate Highway System.

Eisenhower's support of the Federal-Aid Highway Act of 1956 can be attributed to his experiences in 1919 as a participant in the U.S. Army's first Transcontinental Motor Convoy across the United States on the Lincoln Highway, which was the first road across America. The convoy left Washington D.C. on July 7 and reached San Francisco on September 6, with several stops along the way. During the trip, bridges cracked, vehicles became stuck in mud, and equipment broke. These challenges, along with the German autobahn network, inspired Eisenhower to support construction of the Interstate System when he became President.

Eisenhower announced his “Grand Plan” for highways in 1954, which led to the Federal-Aid Highway Act that was signed on June 29, 1956. The Act created the Highway Trust Fund to fund and accelerate construction of the Interstate System. The money paid for 90% of the highway construction costs, and the states paid the remaining 10%. The money was generated through new taxes on fuel, automobiles, trucks, and tires.

In total, $25 billion was appropriated for the construction of 41,000 miles of Interstate Highways over a 20-year period. At the time, it was the largest public works project in American history.