The Communist Party USA (CPUSA) is a communist political party in the United States established in 1919 after a split in the Socialist Party of America.
The CPUSA has a long, complex history that is closely tied with the American labor movement and the histories of communist partiesworldwide. The party was influential in American politics in the first half of the 20th century and played a prominent role in the labor movement from the 1920s through the 1940s, becoming known for opposing racism and racial segregation. Its membership increased during the Great Depression, but the CPUSA subsequently declined due to events such as the second Red Scare and the influence of McCarthyism while its support for the Soviet Union increasingly alienated it from the rest of the left in the United States in the 1960s.
The CPUSA opposed glastnost and perestroika in the Soviet Union and as a result major funding from the Communist Party of the Soviet Union was ended in 1989. The party remains committed to Marxism–Leninism.