Final answer:
President Eisenhower's primary focus in the creation of the Interstate Highway system was National defense and mobility. The network served an important military purpose, making it easier to deploy troops in case of a national emergency.
Step-by-step explanation:
President Eisenhower's main concern when proposing the Interstate Highway Act was c) National defense and mobility. In the late 1940s, the interstate highway system was conceived as a network to ease commuting to and from cities, but also served an important military purpose. Interstate highways made it easier to deploy troops in case of a national emergency and facilitated national defense.
Additionally, the nationwide infrastructure upgrade significantly impacted the American economy and society. Industries expanded to keep up with auto production, suburbs changed, and new businesses emerged to service millions of Americans who were now able to travel extensively and easily due to this transportation revolution.
To summarize, while the Interstate Highway Act brought about notable changes in various aspects of American life, its primary aim rested in advancing national defense and improving nationwide mobility.
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