1. Russian Revolution: The Bolsheviks' rise to power in Russia's 1917 revolution created fear among many people, including American industrialists and politicians, who saw communism as a threat to capitalism and democracy.
2. The First Red Scare: Immediately following World War I(1917-1920) fears of an imminent communist revolution in the United States led to a series of government raids and arrests, targeting suspected radicals and immigrants from Eastern Europe. This period saw Palmer raids, during which thousands were arrested and deported without due process.
3. World War II and the Cold War: The end of World War II saw the beginning of Cold War, the ideological conflict between the US and the Soviet Union. This competition for global influence created an environment of fear and suspicion.
4. Soviet Expansion: The Soviet Union's rapid expansion after the war, through the establishment of communist governments in Eastern Europe, further added to the US fear of communist influence spreading worldwide.
5. Atomic Bomb Espionage: The discovery that the Soviet Union had developed atomic weapons in the late 1940s, despite American efforts to keep the technology a secret, intensified the fear of communist infiltration.
6. Alger Hiss Case: The trial and conviction of Alger Hiss in 1948 ,a high-ranking government official, on charges of spying for the Soviet Union, fueled belief in communist espionage within the US government.
7. Hollywood Blacklisting: The film industry was affected by the red scare, with the creation of blacklists that prevented suspected communist sympathizers from working in Hollywood.
8. McCarthyism: The period between the late 1940s and late 1950s is often referred to as the McCarthy era due to the influence of Senator Joseph McCarthy. McCarthy made several unsubstantiated accusations of communism against government officials and citizens. His tactics of using public accusations and fear to undermine the reputations and livelihood of individuals caused substantial damage to civil liberties and created a tense political climate.
These events contributed to the creation of an atmosphere of suspicion, paranoia, and fear in American society, leading to the Second Red Scare and restrictive policies aimed at rooting out suspected communist or communist sympathizers in the United States.