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The Encyclopedia of Oklahoma History and Culture


Born in New York on September 23, 1878, Hector Marvin Sinclair moved to Oklahoma and settled in the McAlester area. He became active in the Oklahoma Socialist Party, serving as Pittsburg County secretary and later as the state party secretary from 1913 to 1920. Sinclair assisted in the decentralization of the state party by returning organizational autonomy from the national and state to the county and local levels.

As an outspoken opponent of Pres. Woodrow Wilson's economic policies, Sinclair encouraged farmers and other laborers to break their allegiance to the Democratic and Republican parties and to join the Socialist Party. He wrote numerous articles noting the plight of America's working poor. Sinclair's writings took a Marxist tone as he explained the capitalist system and Wilson's agricultural policies, which gave landlords, bankers, and merchants the majority of federal farm subsidies while the tenant farmer and other laborers continued to live a subsistence lifestyle.

The Oklahoma Socialist Party experienced tremendous success during Sinclair's early days as state party secretary. He focused primarily on increasing grass roots support through canvassing local voters and conducting encampment tours throughout the state. Sinclair's tactics proved successful. In 1914 six Socialist candidates won seats in the Oklahoma Legislature, and 175 won election to local and county offices. By 1915 the party doubled its membership to fifteen thousand. In the 1916 election 45,091 Oklahomans voted Socialist. However, the party's rise in popularity was short lived.

In 1917 the party began to decline as a result of the Green Corn Rebellion and the Red Scare. Editorials in mainstream publications such as Harlow's Weekly associated socialism with the rebellion as well as anarchy and revolution. Although Sinclair appeared sympathetic to those farmers who participated in the rebellion, he attempted to distance the party from radical elements. Advocating a nonviolent approach, Sinclair wrote that political action rather than violence was the only viable option in assisting the working class. Both state and federal sedition laws, however, continued to repress the Socialist Party. Socialists experienced harassment, intimidation, and suppression of their First Amendment rights of free speech and assembly. The threat of arrest and persecution destroyed the Socialist Party organization as well as its membership.

Party membership plummeted from ten thousand in 1916 to thirty-five hundred in 1917. Moreover, in the 1918 election only seventy-five hundred Oklahomans voted socialist. Sinclair attempted to save the party by denouncing war profiteers and encouraging Oklahoma Socialists to stand firm in the face of adversity. His efforts fell short, and the Oklahoma Socialist Party continued to decline. By 1924 the party had all but disappeared from the Oklahoma political landscape. Sinclair later moved to Riverside, California, where he died on March 11, 1951.

Connie G. Armstrong

Learn More

Jim Bissett, Agrarian Socialism in America: Marx, Jefferson, and Jesus in the Oklahoma Countryside, 1904–1920 (Norman: University of Oklahoma Press, 1999).

Garin Burbank, When Farmers Voted Red: The Gospel of Socialism in the Oklahoma Countryside, 1910–1924 (Westport, Conn.: Greenwood Press, 1976).

James R. Green, Grass-Roots Socialism: Radical Movements in the Southwest, 1895–1943 (Baton Rouge: Louisiana State University Press, 1978).


The following (as per The Chicago Manual of Style, 17th edition) is the preferred citation for articles:
Connie G. Armstrong, “Sinclair, Hector Marvin,” The Encyclopedia of Oklahoma History and Culture, https://www.okhistory.org/publications/enc/entry?entry=SI008.

Published January 15, 2010

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