The Palmer Raids were a series of raids conducted by the United States Department of Justice to capture, arrest and deport suspected radical leftists, especially anarchists, from the United States. The raids and arrests occurred in November 1919 and January 1920 under the leadership of Attorney General A. Mitchell Palmer. Though more than 500 foreign citizens were deported, including a number of prominent leftist leaders, Palmer's efforts were largely frustrated by officials at the U.S. Department of Labor, which had authority for deportations and objected to Palmer's methods.
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. 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.
During the First World War, there was a nationwide campaign in the United States against the real and imagined divided political loyalties of immigrants and ethnic groups, who were feared to have too much loyalty for their nations of origin. Particular targets were Germans, with sympathies for their homeland, and Irish, whose countrymen were in revolt against America's ally, the United Kingdom. In 1915, President Wilson warned against hyphenated Americans who, he charged, had "poured the poison of disloyalty into the very arteries of our national life." "Such creatures of passion, disloyalty and anarchy", Wilson continued "must be crushed out". The Russian Revolution of 1917 added special force to fear of labor agitators and partisans of ideologies like anarchism and communism. The general strike in Seattle in February 1919 represented a new development in labor unrest that the war had suppressed.