Socialist Party of America
The Socialist Party of America was formed in 1901 by a merger between the Social Democratic Party of Eugene V. Debs, formed three years earlier by veterans of the Pullman Strike of the American Railway Union, and a wing of the older Socialist Labor Party.
Prominent members included Helen Keller, Upton Sinclair, Carl Sandburg, and Jack London.
Before World War I, it elected two Members of Congress, over 70 mayors, and many state legislators and city councilors. Opposition to the war reduced its popularity, while its best-known member, Debs, was imprisoned on treason charges. In 1919 there was a major split, when many native members split to form the Communist Labor Party, led by John Reed. The SP had also counted as members large foreign language federations which were autonomous and they also broke away to form the Communist Party of America. The two Communist Parties later becoming one.
The Socialist Party did not run a presidential candidate in 1924, but joined the AFL and railroad brotherhoods in support of independent Sen. Robert M. La Follette of Wisconsin. In 1928, the Socialist Party revived as an independent electoral entity under the leadership of Norman Thomas, a founder of the American Civil Liberties Union. Thomas would remain the SPUSA Presidential candidate and leader until after World War Two.
During the 1930's the party experienced growth particularly among youth and turned leftwards politically. A left wing caucus was formed called the Clarity caucus to argue for more left wing policies. This led to the formation of the Social democratic federation by some of the Old Guard, as they were described, who then left the SP. This deepened the turn to the left.
The youth were organised in the Young Peoples Socialist League. Also in the 1930s and as a result of the left turn taken by the party the small Trotskyist movement dissolved it's organisation, at that point named the Workers Party, and joined the Socialists. In a short time they won a great deal of support particularly amongst the youth of the YPSL. At the end of 1938 this led to the Trotskyists leaving the SP to form their own Socialist Workers party and Yoiung Peoples Socialist League (Fourth Internationalist).
The party's anti-war stance further weakened it during World War II, and it was hurt by the anti-Communist drives of the McCarthy era. In the succeeding decades, the party was rent by internal dissent.
In 1958 the SP admitted to its ranks the members of the Independent Socialist League led by former Trotskyist Max Shachtman who was now moving rightwards. Some of his more youthful supporters however rejected his right move and worked in the Young Socialist League of the SP until they left the SP entirely in the early 1960s to form the Indepedent Socialist Committee. Meanwhile Shachtman emerged as the leader of the right wing of the SP.
In 1973 the Socialist Party of America was taken over by right-Shachtmanites and renamed the Social Democrats USA. A faction led by Michael Harrington became the Democratic Socialists of America and a third faction led by David McReynolds formed the Socialist Party USA.