- Longtime socialist
- Union leader and activist
- Advocated for the revolutionary overthrow of capitalism
Born December 14, 1852 in Curaçao, Daniel De Leon studied medicine at the University of Leiden in the Netherlands but never earned an MD degree. Sometime between 1872 and 1874 he emigrated with his wife and mother to New York, where he found work as an instructor in Latin, Greek and mathematics at a suburban school. After earning an LLB from Columbia College in 1878, De Leon spent the next four years as a practicing attorney in Brownsville, Texas and then returned to New York. In 1883 he took a three-year teaching post at Columbia's School of Political Science. He was rehired for a second term in 1886 but was released in 1889.
De Leon became a committed socialist in 1886. Four years later he joined the Socialist Labor Party (SLP) and became the editor of its newspaper, The People. In 1891, 1902, and 1904, De Leon ran unsuccessfully for the governorship of New York State.
Advocating for the revolutionary overthrow of capitalism, De Leon was highly critical of the trade union movement in America because of its inclination to work within the capitalist system rather than topple it. When unions concentrated on practical matters, such as higher pay and shorter work weeks, De Leon denounced them as “buffers of capitalism,” “labor lieutenants of the capitalist class,” and “pure and simplers”—a reference to American Federation of Labor (AFL) leaders who considered their union a “pure and simple” trades union rather than a political organization. Citing “the impossibility of obtaining a decent living while capitalism existed,” De Leon wanted the conditions of workers to deteriorate dramatically, so as to escalate their clamors for socialism. He forbade members of his political party from holding office in the AFL and other traditional labor unions:
“No organization of labor can accomplish anything for the workers that does not proceed from the principle that an irrepressible conflict rages between the capitalist and the working class, a conflict that can be settled only by the total overthrow of the former and the establishment of the Socialist Commonwealth.”
In 1893, De Leon captured a garment workers’ local in order to lay the groundwork for his larger plan—to seize control of the floundering Knights of Labor, and then, the fledgling AFL. The tactic would become known as “boring from within,” infiltrating an organization for the purpose of reorienting it. By 1895, however, the garment workers rid themselves of De Leon.
In 1895 De Leon established the Socialist Trade and Labor Alliance (STLA). But the STLA died a decade after its founding with less than a tenth of its original membership.
In 1904 De Leon attended the International Socialist Congress, held in Amsterdam. Under the influence of the American Labor Union (ALU), he altered his politics to focus more intently on industrial unionism. He worked with the ALU to establish the Industrial Workers of the World (IWW) in Chicago in 1905. But before long, De Leon was embroiled in policy disputes with other IWW leaders, whom he characterized as “the bummery” and "slum proletarians." When the IWW ejected De Leon in 1908, he responded by moving to Detroit and forming a new, smaller outfit, also called the Industrial Workers of the World, which De Leon said represented the true IWW. The new group was renamed the Workers' International Industrial Union in 1915, and collapsed in 1925.
The famed Communist John Reed (1887-1920) once stated that “Premier Lenin is a great admirer of Daniel DeLeon. He considers him the greatest of modern socialists—the only one who has added anything to socialist thought since Marx.”
De Leon died in New York on May 11, 1914.