Denis Kearney (1847-1907) was a charismatic Irish immigrant who became the leader of the virulently anti-Chinese San Francisco Workingman's Party in the 1870s. Kearney believed that unemployment and misery for white workers were the result of unfair competition from Chinese "coolie" laborers, who would work for much lower wages than those typically earned by American workingmen.
During the 1870s, Kearney turned the Workingman's Party into a force in California politics. Kearney's allies controlled the city government of San Francisco and made up a large majority in the California state legislature. His slogan—"Chinese Must Go!"—carried all the way to Washington, D.C., where the San Francisco Workingmen's agitation raised the issue of Chinese immigration to national prominence. Perhaps no other individual was as instrumental as Kearney in pushing Congress to adopt the Chinese Exclusion Act of 1882.