De Leon, Daniel

De Leon, Daniel

De Leon, Daniel (dē lēˈŏn), 1852–1914, American socialist leader. Born on the island of Curaçao of Spanish-American parents, he was educated in Germany and the Netherlands before going (1872) to New York City. There he edited a Spanish newspaper, studied law at Columbia (LL.B., 1876), practiced law for a few years, and then returned to Columbia to lecture (1883–89) on Latin American diplomacy. His interest in labor reform grew, and he joined successively the Knights of Labor (1888), Edward Bellamy's “Nationalist” movement (1889), and the Socialist Labor party (1890).

De Leon was the Socialist Labor candidate for governor of New York in 1891, and for years he edited the Socialist Labor weekly, The People. He was an inflexible and doctrinaire Marxian revolutionist and consequently fell out with most other liberal leaders. He opposed unionization of labor according to trades and led the group that formed the Socialist Trade and Labor Alliance, but his leadership was too radical for some of the members (prominent among them Morris Hillquit), who withdrew in 1899 and ultimately formed the Socialist party.

De Leon's prestige subsequently lessened. He helped to found the Industrial Workers of the World in 1905, but in the quarrel over political action he and his followers were expelled. The rival Workers' International Industrial Union, which he then organized, did not flourish. He wrote a great deal of Socialist polemical literature and translated a work of Karl Marx.


See A. Peterson, Daniel De Leon, Social Architect (2 vol., 1941–53); study by L. G. Raĭskiĭ (1959); C. Reeve, The Life and Times of Daniel DeLeon (1972); bibliography by O. C. Johnson (1966).

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De Leon, Daniel


Born Dec. 4, 1852, on the island of Curasao, in the Netherlands Antilles; died May 11, 1914, in New York. A leader of the workers’ movement in the USA.

De Leon was educated in Germany, the Netherlands, and the USA, where he moved in 1872. He lectured in law at Columbia University from 1883 to 1889. In 1890 he joined the Socialist Labor Party (SLP) and soon became its leader and ideologist. In 1891, De Leon became the editor of People, the official organ of the SLP. He defended the idea of the class struggle and opposed craftguild mentality and the ideology of trade unionism. He led the struggle against the rightist and centrist leaders of the SLP and the reformist leaders of the American Federation of Labor (AFL). De Leon exposed the policy of the opportunist leaders of the Second International. However, he committed serious sectarian errors and ignored the significance of the struggle for the everyday demands of the workers. De Leon was defeated in the struggle within the AFL and called on socialists and revolutionary-minded workers to leave the organization. In 1905 he participated in the creation of the Industrial Workers of the World. At the same time, De Leon rejected the leading role of political parties in the labor movement and the necessity for the dictatorship of the proletariat, thus in effect agreeing to the bourgeois theory that America was an exception to general historical laws.


Speeches and Editorials, vols. 1–2. New York, 1923–30.
Industrial Unionism. New York, 1920.


Zubok, L. I. Ocherki istorii rabochego dvizheniia v SShA. Moscow, 1962.
Foner, F. Istoriia rabochego dvizheniia v SShA, vol. 2. Moscow, 1958.
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

De Leon, Daniel

(1852–1914) socialist advocate; born on the island of Curaçao. He studied in Europe before he emigrated to New York City (1874), becoming a lawyer (1878) and lecturer on Latin-American diplomacy at Columbia University (1883–86). Joining the Socialist Labor Party (1890), he was named its national lecturer (1891) and editor of its organ, The People (1892), and was an unsuccessful candidate for governor and Congress. A lifelong leader of the party, antagonistic to existing trade unions, his intrangiency eventually led to formation of a splinter group, the Socialist Party of America. In 1905 he also assisted in the formation of the Industrial Workers of the World (IWW), which soon splintered; he was ousted from the IWW and formed his own Workers' International Industrial Union. To opponents he was a disruptive fanatic; to supporters a man of incorruptible integrity. Lenin praised his writings as incorporating the germ of the Soviet system.
The Cambridge Dictionary of American Biography, by John S. Bowman. Copyright © Cambridge University Press 1995. Reproduced with permission.
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Respondents from the Estradaappointed board were led by then PEA Chair Francisco San Juan, with Carlos Doble, Carmelita de Leon, Daniel Dayan, Salvador Malbarosa, Leo Padilla and Elpidio Damaso.