Final answer:
The Interstate Highway Act, passed in 1956, contributed to the improvement of transportation and economic growth in the United States.
Step-by-step explanation:
The Interstate Highway Act, passed in 1956, contributed to the solution of improving transportation and promoting economic growth in the United States. The act led to the construction of the federal interstate system, consisting of 40,000 miles of highways. This new highway system facilitated the movement of troops and equipment, which was crucial for national defense, and also provided a network of roads for private and commercial transportation. The interstate highways improved the ability to travel across the nation by automobile, but also bypassed small towns and older commercial centers, leading to the devastation of some businesses and communities.