what was the name of This was the period after each world war which saw massive upheaval in the U.S. and fear of many foreigners. It was characterized by widespread fears of Communist influence on U.S. society and Communist infiltration of the U.S. government.

Answer 1

The period you're referring to is known as the "Red Scare." There were two main Red Scares in the United States: the first occurred after World War I, roughly from 1917 to 1920, and the second took place after World War II, particularly in the late 1940s and throughout the 1950s. The second Red Scare is often associated with McCarthyism, named after Senator Joseph McCarthy, who famously conducted investigations and hearings aimed at uncovering alleged Communist subversion.