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.