How did the McCarthy era affect Americans?

All communists were unemployed. The only way for a "communist" to stay out of jail, or to keep a steady job, was to give names of other "communists". Since many of the accused were not truly communists, they did not know any other communists. This caused many innocent people to be accused.

It caused the blacklisting of actors, actresses, writers, directors, etc. in the film Industry because of the Red Scare.

McCarthyism was a campaign, led by Senator Joseph McCarthy, against alleged communists in the US government and other institutions. Some of its effects were the loss of jobs, the fear and trauma it caused for the victims and the stifling of progress and individual expression.