Which of the following contributed to the red scare in the united states?
russian revolution
treaty of versailles
league of nations

The Russian Revolution contributed to the Red Scare in the United States. The correct option in regards to the question given is the first option. The Boston Police strike during the year 1919 along with the labour strikes of 1920 made the Americans fearful. The Americans thought that several immigrants coming into United States may be trying to destabilize the country by importing communism to the country. The Americans thought that this would destroy the philosophy on which the country stood. this led them to gather all immigrants and deport them. although many were not involved but still they were made scapegoat of the situation.