Denis Kearney (1847-1907) was the leader of California's Workingmen's Party. Born in Ireland, he went to sea at age 11 as a cabin boy and rose to the rank of first mate by the time he first visited San Francisco in 1868. He settled in San Francisco in 1870 and opened a drayage business. Interested in philosophy and politics, Kearney emerged as a powerful speaker and organizer among San Francisco's working classes at "sand lot" meetings held on the empty lots near city hall in the 1870s.
In 1877, Kearney played a leading role in the formation of the Workingmen's Party. Fueled by class and race antagonism, Kearney and the party attacked the economic and political power of industrial elites like the Big Four as well as the Chinese immigrants that competed with native workers for jobs. The Workingmen's Party built a following throughout the state in 1878, elected a third of the delegates to the state's constitutional convention, and managed to place diluted versions of their proposals in the new constitution. The party also elected several legislators and senators to the state government in 1879. But within two years, the party had all but disappeared from California politics.
Kearney attempted to rebuild the working class coalition as a member of the Greenback Party, but improved economic conditions diminished the appeal of political activism. Kearney retreated to public life and rebuilt his hauling business.