Defense Interstate Highway Act of 1956 is adopted in Washington, D.C.

The law is passed by Congress and signed by President Dwight Eisenhower, who calls it the largest public works program “ever undertaken by the United States or any other country.” The law dramatically expands the 1944 Federal-Aid Highway Act, makes interstate highway construction eligible for 90% federal funding, and subsequently leads to the construction of 40,000 miles of highways, including a number in and around Boston.