The Red Scare
"After World War I, a wave of socialist-inspired labor riots and even bombings in America prompted many Americans to demand further immigration restrictions. The specter of an imported brand of foreign radicalism, seemingly confirmed by the robbery and murder convictions of Italian-born anarchists Sacco and Vanzetti, loomed over the nation's urban centers. " – “Our New Immigration Policy” 1924 [1\
At the same time, the Red Scare in America prompted politically driven fears of foreign radicalists infiltrating the country and overthrowing the government, parallel to the events of the Russian 1917 Bolshevik Revolution in which communists seized control.