an increase in the populations of midwestern and western cities
Explanation:
The construction of the Interstate Highway Network was authorized by the Federal Aid Highway Act of 1956, popularly known as the Interstate and Defense Highways Act of 1956.
It was a petition of the largest automobile manufacturers in the United States and promoted by President Dwight D. Eisenhower - influenced by his experiences as a young soldier crossing the United States in 1919 following the route of the Lincoln Highway and the knowledge of the motorway network German (Autobahnen) during World War II - as a necessary component of a national defense system. This would make possible a better displacement by land of troops and military supplies.
