The period of time during the 1920s when there was a fear of Communism growing in the United States was known as what?
The First Red Scare
A short period from 1919 to 1920 when the Russian Revolution and other influences caused a fear of Socialist and Anarchist elements of American society.
This was partly due to the Nationalism brought on by World War 1 and partly due to U.S. government actions to suppress such elements as well as pro-German elements as part of the war effort.
A general uprising was expected on May 1, 1920 which did not materialize. After this the concern faded.