Federal-Aid Highway Act of 1956

The Federal-Aid Highway Act of 1956, popularly known as the National Interstate and Defense Highways Act, was enacted on June 29, 1956, when Dwight D. Eisenhower signed the bill into law. With an original authorization of 25 billion dollars for the construction of 41,000 miles of Interstate Highway System supposedly over a 20-year period, it was the largest public works project in American history through that time. The money for the Interstate Highway and Defense Highways was handled in a Highway Trust Fund that paid for 90 percent of highway construction costs with the states required to pay the remaining 10 percent. It was expected that the money would be generated through new taxes on fuel, automobiles, trucks, and tires. As a matter of practice, the Federal portion of the cost of the Interstate Highway System has been paid for by taxes on gasoline and diesel fuel.


Eisenhower's support of the Federal-Aid Highway Act of 1956 can be directly 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 historic Lincoln Highway, which was the first road across America. The highly publicized 1919 convoy was intended, in part, to dramatize the need for better main highways and continued federal aid. The convoy left the Ellipse south of the White House in Washington D.C. on July 7, 1919, and headed for Gettysburg, Pennsylvania. From there, it followed the Lincoln Highway to San Francisco. Bridges cracked and were rebuilt, vehicles became stuck in mud, and equipment broke, but the convoy was greeted warmly by communities across the country. The convoy reached San Francisco on September 6, 1919. Eisenhower argued for the highways for the purpose of national defense. In the event of a ground invasion by a foreign power, the U.S. Army would need good highways to be able to transport troops across the country efficiently. Following completion of the highways the cross-country journey that took the convoy two months in 1919 was cut down to two weeks.