What organization did Denis Kearney lead to oppose Chinese immigration?

Denis Kearney was a prominent labor leader in California during the late 19th century, particularly known for his ardent opposition to Chinese immigration. He led the Workingmen's Party of California, an organization founded in 1876 that sought to unite various labor groups to address issues affecting workers at the time. The party's platform and Kearney's fiery speeches often focused on the belief that Chinese immigrants were taking jobs from white workers and driving down wages. This rhetoric resonated with many American laborers who felt threatened by the competition.

The Workingmen's Party gained significant influence in California politics during this period, pushing for legislation that aimed to restrict Chinese immigration and establish more favorable working conditions for white laborers. Kearney's activism and the efforts of the party played a crucial role in shaping public perceptions and policies related to immigration in California, including the eventual passage of the Chinese Exclusion Act in 1882.

In contrast, the other organizations listed either did not focus on immigration issues specifically or were established for different purposes, making the Workingmen's Party of California the correct answer to the question regarding Kearney's leadership against Chinese immigration.