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 •
Martin Abern * •
Devere Allen •
Elmer Allison * •
E.B. "Harry" Ault •
J. Mahlon Barnes •
David P. Berenberg •
Victor L. Berger, Congressman from
Milwaukee •
Barney Berlyn •
Allan L. Benson, 1916 candidate for Vice-President •
Ella Reeve Bloor * •
Roy E. Burt •
Frank Bohn IWW •
Earl Browder *, Communist Party leader and presidential candidate •
James P. Cannon *, leader of the Communist Party and
Socialist Workers Party •
Jack Carney •
Travers Clement •
Joseph Coldwell •
James Connolly, Irish labor and nationalist leader •
Eugene V. Debs IWW, labor organizer, Presidential candidate •
David Dubinsky, labor leader •
Max Eastman *, writer •
J. Louis Engdahl •
William M. Feigenbaum, New York assemblyman 1918 •
Elizabeth Gurley Flynn *, IWW and Communist leader •
William Z. Foster *, Communist leader and presidential candidate •
Louis Fraina * •
Joseph Freeman * •
Samuel Friedman, Vice-presidential candidate •
Charles B. Garfinkel, New York assemblyman 1918, temporary chairman of the NYC central committee SPA in 1935 after Old Guard was expelled •
Julius Gerber •
Adolph Germer •
Arturo Giovannitti •
Benjamin Gitlow * •
Carl Haessler * •
Emanuel Haldeman-Julius SDL •
Job Harriman, Vice-presidential candidate •
Michael Harrington DSOC, author •
Hubert Harrison •
Max S. Hayes, labor leader •
Bill Haywood IWW •
Emil Herman •
George D. Herron •
Morris Hillquit ISS, labor lawyer, New York mayoral candidate •
Daniel Hoan, mayor of Milwaukee •
Darlington Hoopes SPUSA •
Jessie Wallace Hughan ISS •
Henry Jager, NY assemblyman 1921 •
Haim Kantorovitch •
William KarlinSDF, lawyer, NY assemblyman 1918 •
Helen Keller •
Charles H. Kerr, publisher •
George R. Kirkpatrick •
Antoinette Konikow * •
Frederick Krafft •
Maynard C. Krueger •
William F. Kruse * •
Leo Krzycki, chairman •
Harry W. Laidler ISS •
Algernon Lee ISS, SDF •
Walter Lippman, journalist •
Jack London ISS •
Meyer London, Congressman from New York City •
George R. Lunn, mayor of
Schenectady, New York •
Theresa S. Malkiel •
Mary Marcy •
James H. Maurer SDF •
Jasper McLevy SDF, mayor of
Bridgeport, Connecticut •
David McReynolds SPUSA, peace advocate, SPUSA presidential candidate •
Herbert M. Merrill, secretary of the SPA-NY, first Socialist New York assemblyman (1912) •
Walter Thomas Mills •
Tom Mooney •
Thomas J. Morgan •
Gustavus Myers •
Scott Nearing •
Reinhold Niebuhr, theologian •
Santeri Nuorteva •
Kate Richards O'Hare •
James Oneal SDF •
Mary White Ovington, co-founder of the
NAACP •
Joseph Arthur Padway •
Jacob Panken, New York municipal judge •
A. Philip Randolph SDF, SDUSA, labor and civil rights leader •
John Reed *, author •
Victor Reuther DSOC, labor organizer •
Walter Reuther, labor organizer •
Elmer Rosenberg, New York assemblyman 1918 •
Charles Edward Russell, writer •
Bayard Rustin SDUSA, civil rights organizer •
Carl Sandburg, poet •
Margaret Sanger, advocate of
family planning •
Roland D. Sawyer •
Edmund Seidel, New York state senator 1921–1922 •
Clarence Senior •
Max Shachtman •
Abraham I. Shiplacoff, NY assemblyman 1916, 1917, 1918 •
Upton Sinclair ISS, writer, organized
End Poverty in California (EPIC) •
John W. Slayton •
John Spargo SDL, writer •
Seymour Stedman •
Charles P. Steinmetz, physicist •
A.M. Stirton, publisher of
The Wage Slave, candidate for governor in Michigan in 1908 •
J.G. Phelps Stokes ISS, SDL, social reformer •
Rose Pastor Stokes *, social reformer •
Maurice Sugar •
Norman Thomas, peace advocate, Presidential candidate •
Henry M. Tichenor •
Hermon F. Titus •
Gus Tyler, writer and labor leader •
Ernest Untermann •
Charles H. Vail •
Baruch Charney Vladeck •
Alfred Wagenknecht * •
Louis Waldman SDF •
Julius Wayland, publisher of
The Appeal to Reason •
Joseph A. Whitehorn, lawyer, New York assemblyman 1917, 1918 •
George W. Woodbey, preacher and African-American leader •
John M. Work •
Frank P. Zeidler SPUSA, mayor of Milwaukee, SPUSA presidential candidate