Federal-Aid Highway Act of 1956

The Federal-Aid Highway Act of 1956, also known as the National Interstate and Defense Highways Act, was enacted on June 29, 1956, when President Dwight D. Eisenhower signed the bill into law. With an original authorization of $25 billion (equivalent to $ in ) for the construction of of the Interstate Highway System over a 10-year period, it was the largest public works project in American history through that time. The addition of the term defense in the act's title was because some of the original cost was diverted from defense funds. 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. Historical background of the Interstate Highway System