query: When did the Socialist Party in the US disband?
passage: Socialist Party of America
The Socialist Party of America (SPA) was a multi-tendency democratic socialist and social democratic political party in the United States formed in 1901 by a merger between the three-year-old Social Democratic Party of America and disaffected elements of the Socialist Labor Party of America which had split from the main organization in 1899.[1]
passage: History of the socialist movement in the United States
Reunification with the Social Democratic Federation (SDF) was long a goal of Norman Thomas and his associates remaining in the Socialist Party. As early as 1938, Thomas had acknowledged that a number of issues had been involved in the split which led to the formation of the rival SDF, including "organizational policy, the effort to make the party inclusive of all socialist elements not bound by communist discipline; a feeling of dissatisfaction with social democratic tactics which had failed in Germany" as well as "the socialist estimate of Russia; and the possibility of cooperation with communists on certain specific matters". Still, he held that "those of us who believe that an inclusive socialist party is desirable, and ought to be possible, hope that the growing friendliness of socialist groups will bring about not only joint action but ultimately a satisfactory reunion on the basis of sufficient agreement for harmonious support of a socialist program". Following directions from the Soviet Union, the Communist Party USA (CPUSA) and its members were active in the Civil Rights Movement for African Americans. Following Stalin's "theory of nationalism", the CPUSA once favored the creation of a separate "nation" for negroes to be located in the American Southeast. In 1941, after Germany invaded the Soviet Union, Stalin ordered the CPUSA to abandon civil rights work and focus supporting American entry into World War II. Disillusioned, Bayard Rustin began working with members of the Socialist Party USA (SPUSA) of Norman Thomas, particularly A. Philip Randolph, the head of the Brotherhood of Sleeping Car Porters. The Socialist Party and the SDF merged to form the Socialist Party–Social Democratic Federation (SP–SDF) in 1957. A small group of holdouts refused to reunify, establishing a new organization called the Democratic Socialist Federation (DSF). When the Soviet Union led an invasion of Hungary in 1956, half of the members of communist parties around the world quit and in the United States half did and many joined the Socialist Party. Frank Zeidler was an American socialist politician and mayor of Milwaukee, Wisconsin, serving three terms from April 20, 1948 to April 18, 1960. He was the most recent socialist mayor of any major American city. Zeidler was Milwaukee's third socialist mayor after Emil Seidel (1910–1912) and Daniel Hoan (1916–1940), making Milwaukee the largest American city to elect three socialists to its highest office.
In 1958, the SPUSA welcomed former members of the Independent Socialist League (ISL), which before its 1956 dissolution had been led by Max Shachtman. Shachtman had developed a Marxist critique of Soviet communism as "bureaucratic collectivism", a new form of class society that was more oppressive than any form of capitalism. Shachtman's theory was similar to that of many dissidents and refugees from Communism, such as the theory of the "new class" proposed by Yugoslavian dissident Milovan Djilas. Shachtman's ISL had attracted youth like Irving Howe, Michael Harrington, Tom Kahn and Rachelle Horowitz. The Young People's Socialist League was dissolved, but the party formed a new youth group under the same name.