How did the rise of the mass media and marketing affect the kind of people Americans admired and imitated?"

Mass media is a very popular means of communication which can reach to public in a very short period of time. Mass media spread information very fast and people also get affected by it.

Explanation:

Mass media was first popularized during 1920s. Radio, television are the very important source of mass communication which spreads news very quickly. People can be aware if they regularly follow one of these means. Business and commerce both are effected by it. American commercialism affected hugely by mass communication.

In 1920s the most popular mean of mass communication was radio. As radio was very popular so keep its service ongoing several number of radio stations were introduced. Then its broad casting system was also enriched.