The Red Scare of 1919 refers to the widespread fear of communism and anarchism in the United States following World War I, marked by heightened anti-immigrant sentiment and a series of government actions aimed at suppressing perceived threats. This period was characterized by significant social unrest, labor strikes, and violent actions against radicals, leading to government crackdowns like the Palmer Raids. The Red Scare reflected the anxiety of a nation transitioning from wartime to peacetime and grappling with internal divisions.