List of members of the Socialist Party of America

Key:

* Went on to join the Communist Party, Communist Labor Party of America or Workers Party of America

^ISS A founder or key member of the Intercollegiate Socialist Society, 1905, later League for Industrial Democracy

^IWW A founder of the Industrial Workers of the World, 1905.

^SDL Left to found the Social Democratic League of America, 1917.

^SDF Left to found the Social Democratic Federation, 1936.

^IPN Left to found the Independent Party of Norwalk, 1951

^SDUSA Continued into Social Democrats, USA, 1973

^SPUSA Went on to join the Socialist Party USA, 1973

^DSOC Went on to join the Democratic Socialist Organizing Committee, 1973, later Democratic Socialists of America

Key:

* Went on to join the Communist Party, Communist Labor Party of America or Workers Party of America

^ISS A founder or key member of the Intercollegiate Socialist Society, 1905, later League for Industrial Democracy

^IWW A founder of the Industrial Workers of the World, 1905.

^SDL Left to found the Social Democratic League of America, 1917.

^SDF Left to found the Social Democratic Federation, 1936.

^SDUSA Continued into Social Democrats, USA, 1973

^SPUSA Went on to join the Socialist Party USA, 1973

^DSOC Went on to join the Democratic Socialist Organizing Committee, 1973, later Democratic Socialists of America