Answer :

The statement "The Federal-Aid Highway Act 1956 was the largest federal project in history." is True.

1. The Federal-Aid Highway Act of 1956, also known as the National Interstate and Defense Highways Act, was signed into law by President Dwight D. Eisenhower.

2. This act allocated funds for the construction of a vast interstate highway system across the United States.

3. It was indeed one of the largest public works projects in American history, spanning over 41,000 miles and costing billions of dollars.

4. The highway system revolutionized travel and commerce in the United States, connecting cities and states like never before.

Therefore, the statement is true as the Federal-Aid Highway Act of 1956 was indeed one of the largest federal projects in history due to its significant impact on the country's infrastructure and transportation network.