The Progressive Labor Party (PLP) is a Marxist-Leninist political party based primarily in the United States. The organization was established in January 1962 as the Progressive Labor Movement following a split in the Communist Party, USA, donning its new name at a convention held in the spring of 1965. The organization played a vocal role in the anti-Vietnam War movement of the 1960s and early 1970s through its Worker Student Alliance faction of Students for Democratic Society. Following termination of American involvement in the Vietnam War, the PLP emerged as one of the leading anti-revisionist Communist organizations in the United States.