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Solon De Leon Papers

Call Number



1900-1980, inclusive


De Leon, Solon, 1883-
Gottesman, Ruth De Leon (Role: Donor)


2 Linear Feet in 2 record cartons

Language of Materials

Materials are in English.


Solon De Leon, son of Daniel De Leon, Marxist theoretician and leader of the Socialist Labor Party, was a socialist, labor educator and labor journalist. The collection contains correspondence with his father and other SLP leaders, unpublished writings, clippings, and memorabilia.

Historical/Biographical Note

Solon De Leon was born in New York City on September 2, 1883. He was the son of Daniel De Leon, Marxist theoretician and leader of the Socialist Labor Party (SLP). Although his parents were Jewish, he was unaware of this until he was an adult. He graduated from City College in 1902 and after working in Connecticut as a carpenter, house painter, and teacher, he returned to New York in 1905 to work on the SLP publications Daily People and Weekly People as a reporter, re-write man, and assistant editor. He translated "The Sword of Honor, or the Foundation of the French Revolution" by Eugene Sue and "Patriotism and the Worker" by Gustave Herve for publication by the SLP publishing house, New York Labor News Company. De Leon received an MA in economics from Columbia University in 1912 and a social work degree from the New School of Social Work (then the New York School of Philanthropy) in 1913. He was employed by the American Association for Labor Legislation as a field investigator, writer, and researcher, 1912-1920, while continuing to contribute to SLP publications under the pseudonym, Braset Marteau, but became politically and personally estranged from his father and from the SLP and was expelled from the Party in 1918.

He was briefly a member of the Socialist Party of America, joining the Workers' Council group that became part of the Communist party in 1920. De Leon contributed to and helped to edit the Advance, the Amalgamated Clothing Workers of America's newspaper, 1919-1922; was director of the labor research department, Rand School of Social Science, during the 1920s, and edited the American Labor Year Book published by the Rand School. During the 1930s, he taught science and shop at the Walden School, a private progressive school in New York; was a nature and shop counselor at children's summer camps, and, as Bert Grant, wrote a science and nature column for the New Pioneer. From 1943 to 1964 De Leon was assistant research director for the National Maritime Union. He was also active in the Labor Research Association during the 1960s, and was a regular contributor of articles and book reviews to its publication Economic Notes. De Leon was a librarian and French instructor at Kettrell Junior College, a Black college in North Carolina from 1965 to 1967, and died in Ellenville, N.Y., on December 3, 1975.


This collection is arranged alphabetically within each series. Series 8 was added to the colleciton in 2015. These materials have not been arranged by an archivist.

Organized into 8 series:

Missing Title

  1. Research and Writings
  2. Unions
  3. Workers' Education
  4. Political Organizations
  5. Applications
  6. Personal
  7. Addendum
  8. 2015 Accretion

Scope and Content Note

The collection contains correspondence, essays, and fragmentary writings, both handwritten and typed, many touching upon union organization, and the politics and ideology of the American Left. Of special interest is his correspondence (between 1912 and 1914) with Daniel De Leon, Arnold Petersen, and other members of the Socialist Labor Party that capture the ideological conflicts that eventually led to De Leon's estrangement from his father and the Party. Correspondence from 1956-1965 between De Leon and League for Industrial Democracy members including Sidney Henchberg, Harry Laidler, Andrew Shiffrin, and Norman Thomas reflects De Leon's disenchantment with the League's lack of organizational activism. Bitter correspondence from 1964-1965 between De Leon and the president's office of The National Marine Union concerns the abolition of De Leon's position of assistant research director.

Printed materials include flyers, brochures, pamphlets, and arbitration briefs from various labor unions and political organizations, as well as syllabi for courses taught by De Leon and fellow socialists for workers. There is a great deal of material of a personal nature also contained in the collection, consisting of personal and collected poetry, political drama, a scrapbook, a postcard collection, and several job applications for research and civil service work. In addition, materials with references to De Leon consisting of newspaper clippings from The Daily and Weekly People, a political essay, and correspondence between De Leon and members of the Socialist Labor Party and one of its principal leaders, his father Daniel De Leon, have been taken from the Nelson Frank collection and added as an addendum.

An additional box of materials was added to the collection in 2015. These documents consist of correspondence and papers predominantly related to Solon De Leon's participation in labor organizing and education between 1920 and 1980. They also include a number of teaching materials for De Leon's courses in labor research and manuscripts for labor related plays and sketches.

Conditions Governing Access

Materials are open without restrictions.

Conditions Governing Use

Copyright (or related rights to publicity and privacy) for materials in this collection, created by Solon De Leon was not transferred to New York University. Permission to use materials must be secured from Ruth De Leon Gottesman.

Preferred Citation

Identification of item, date; Solon de Leon Papers; TAM 092; box number; folder number; Tamiment Library/Robert F. Wagner Labor Archives, New York University.

Location of Materials

This collection is held offsite. Please contact at least two business days prior to your research visit to coordinate access.

Immediate Source of Acquisition

Donated by Ruth De Leon Gottesman in 1977; an additional accession was donated in 2013. The accession numbers associated with these gifts are 1977.003 and 2015.012.

Collection processed by

Peter J. Arnade

About this Guide

This finding aid was produced using ArchivesSpace on 2023-08-20 16:50:09 -0400.
Using Describing Archives: A Content Standard
Language: Description is in English.

Processing Information

One box of materials was added to the collection as Series 8 in 2015. These materials have been placed into archival housing based on rough groupings supplied by donor. This order has been maintained and folder titles were supplied by archivist when like items appeared to be grouped together.

Edition of this Guide

This version was derived from De Leon, Solon template.doc


Tamiment Library and Robert F. Wagner Labor Archives
Tamiment Library and Robert F. Wagner Labor Archives
Elmer Holmes Bobst Library
70 Washington Square South
2nd Floor
New York, NY 10012