Young People's Socialist League

The Young People's Socialist League began in 1907 as a youth circle in Chicago, Illinois. In 1913 the Young People's Socialist League (YPSL) was established as the Socialist Party's national youth affiliate. As World War I was beginning, YPSL had over 100 branches and almost 10,000 members. In 1919, the Socialist Party's left-wing broke off and formed what would eventually become the Communist Party USA, YPSL decided to follow that faction out of the Socialist Party.

The Great Depression helped rebuild the Socialist Party's YPSL, and by 1932 it had 2,500 members. A faction fight happened in the Socialist Party in 1936 between left-wing "Militants" and a right-wing "Old Guard". YPSL sided with the Militants. The Old Guard lost the faction fight and left the Socialist Party, forming the Social Democratic Federation.

In March 1936, the Trotskyist Workers Party of the United States entered the Socialist Party as part of the French Turn. It remained a faction in the Socialist Party and left in January 1938, taking YPSL with it into the Socialist Workers Party.

By 1952, the Socialist Party's YPSL had 134 members, 62 of which had been recruited that year. The Socialist Party supported the Korean War, which was a less popular position in YPSL, especially considering much of YPSL was of draft age. The Independent Socialist League (ISL) affiliated Socialist Youth League (SYL) had been making overtures to YPSL. SYL members had an anti-war quarterly called Anvil which was theoretically independent, although SYL dominated it, some YPSL members became editors of the quarterly. The Socialist Party told YPSL it couldn't have contact with the "totalitarian" SYL or ISL, although YPSL ignored this, and the relationship between YPSL and the Socialist Party worsened. In 1953, the Socialist Party cut off money to YPSL, and then suspended YPSL's New York branch, which was the one with the most contact with SYL (and the ISL). In August, YPSL, including the "suspended" members, voted to disaffiliate with the Socialist Party. In February 1954, the Young People's Socialist League merged with the Socialist Youth League to form the Young Socialist League.

A very small faction in YPSL didn't go along with the merger and continued to call itself the Young People's Socialist League. In the late 1950's, the Young Socialist League dissolved itself into the group calling itself YPSL. With the upswing of student activism going into the 1960's, YPSL began to grow. YPSL participated in different activities, including helping organize a nuclear test ban march in Washington DC in 1962. YPSL subsequently split into two factions, a left-wing one which wanted to create a mass labor party, and a right-wing one which wanted realignment with the Democratic Party. In 1964, the left-wing faction took over YPSL, before itself breaking into factions. YPSL was dissolved shortly afterward. Two years later it was reconstituted, but remained small throughout the 1960s compared to groups like SDS.

In 1973, the Socialist Party of America had three factions, and each split into a new group. One of them was Socialist Party USA. YPSL became the youth affiliate of the Socialist Party USA in 1989.