<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> The First Red Scare was a period during the early 20th - century history of the United States marked by a widespread fear of Bolshevism and anarchism, due to real and imagined events; real events included the Russian Revolution and anarchist bombings . At its height in 1919--1920, concerns over the effects of radical political agitation in American society and the alleged spread of communism and anarchism in the American labor movement fueled a general sense of concern . </P> <P> The Scare had its origins in the hyper - nationalism of World War I as well as the Russian Revolution . At the war's end, following the October Revolution, American authorities saw the threat of Communist revolution in the actions of organized labor, including such disparate cases as the Seattle General Strike and the Boston Police Strike and then in the bombing campaign directed by anarchist groups at political and business leaders . Fueled by labor unrest and the anarchist bombings, and then spurred on by United States Attorney General A. Mitchell Palmer's attempt to suppress radical organizations, it was characterized by exaggerated rhetoric, illegal search and seizures, unwarranted arrests and detentions, and the deportation of several hundred suspected radicals and anarchists . In addition, the growing anti-immigration nativism movement among Americans viewed increasing immigration from Southern Europe and Eastern Europe as a threat to American political and social stability . </P>

The first red scare in the united states was a reaction to which event