The Palmer Raids occurred in the larger context of the Red Scare , the term given to fear of and reaction against communist radicals in the U.S. in the years immediately following World War I and the Russian Revolution . There were strikes that garnered national attention , race riots in more than 30 cities , and two sets of bombings in April and June 1919 , including one bomb mailed to Palmer 's home . The Palmer Raids preceded the Immigration Act of 1924 , which also targeted Southern European and Eastern Europe immigrants on not just political grounds but also mostly ethnic and racial grounds
two sets of bombings
1919 United States anarchist bombings
Palmer Raids