The labor unrest after World War I happened mainly because of poor working conditions, a lack of employment opportunities, the fear of communism and low wages. Immigration was also a factor because many workers believed that immigrants were taking up the jobs that Americans should have.
Soldiers who returned home from the war in 1918 could not find jobs easily as many prewar jobs had been eliminated, or women and immigrants had filled their roles. Conditions in the factories were not good for the workers, as they worked long hours for little pay. The end of World War I also brought inflation in the economy and the cost of living went up. Communism was in place in Russia and caused the Red Scare in the United States as it spread to more countries. The creation of unions escalated communism fears; some Americans believed unions would lead to communism in the United States because they went against "American beliefs."
Many workers went on strike through the years 1919 to 1921. The 1919 Seattle General Strike was the first general strike in American history. Unions allowed these strikes to happen, so that workers could fight for more pay and better workplace conditions.