Language federation
Language federations were formed in the late 19th and early 20th century by immigrants to the United States, primarily from Eastern and Southern Europe, who shared a commitment to some form of socialist politics. Some of these groups joined the Socialist Labor Party of America (SLP); later, many joined the Socialist Party of America (SPA) and then later joined one of the precursors of the Communist Party USA (CPUSA); a number of federations also remained in the Socialist Party.