The book depicts working class poverty, the lack of social supports, harsh and unpleasant living and working conditions, and a hopelessness among many workers. These elements are contrasted with the deeply rooted corruption of people in power. A review by the writer Jack London called it "the Uncle Tom's Cabin of wage slavery." Sinclair was considered a muckraker, or journalist who exposed corruption in government and business. In 1904, Sinclair had spent seven weeks gathering information while working incognito in the meatpacking plants of the Chicago stockyards for the newspaper. He first published the novel in serial form in 1905 in the Socialist newspaper Appeal to Reason and it was published as a book by Doubleday in 1906.