The ability of foreign enterprises to establish factories in China after the Treaty of Shimonoseki in 1895 accelerated industrialization and as a consequence proletarianization, by which numerous workers without resources entered a class relationship by selling their labor power to survive. It was, however, during the economic boom years of World War I and its aftermath and during the New Culture Movement with the introduction of socialism that new urban social forces—the bourgeoisie and working class—emerged and radical intellectuals applied the concept of social class to their analysis of society and revolution. The increasingly politicized and often-militant quality of the labor movement between 1919 and 1927 led Jean Chesneaux (Chesneaux 1968, cited under Class Formation and the Labor Movement) to argue, in Marxist terms, that a class-conscious proletariat under the ideological guidance of the Chinese Communist Party (CCP) had arisen in reaction to the forces of imperialist oppression and exploitation. Although most social historians of the republican era concur that social classes in their objective form had emerged by the 1920s, they disagree on whether workers constituted a subjective “class for itself.” Scholars influenced by the new labor history school, with its emphasis on community and culture, find the complexity of the social composition and social dynamics of the working class to have obstructed the process of class formation. Despite positing workers’ own historical agency, these scholars underscore how segmented labor markets, workers’ particularistic ties and strong sense of regional identity, and gender divisions impeded class consciousness. Consequently, questions over workers’ politics and the nature of the labor movement have become controversial. Elizabeth J. Perry (Perry 1993, cited under Class Formation and the Labor Movement) interprets labor divisions based on skill, provenance, and gender as encouraging rather than debilitating labor activism. Other studies emphasize how anti-imperialism fueled the 1920s labor movement, with class taking a subservient role to nationalism. In a related issue, the relationship between workers and the CCP has sparked debate. Whereas Chesneaux emphasized that a class-conscious proletariat served as the social basis for the Communist revolution, others have challenged the CCP’s ideological supremacy and leadership over the labor movement and have focused on contradictions between Communists (largely drawn from the intelligentsia) and workers. Although these studies focus on Shanghai, Hong Kong, and Canton from 1919 to 1927, scholarship on Chongqing’s class formation during the 1940s analyzes both objective and subjective features of social class and contributes to an ongoing debate about the origins of the post-1949 work unit (danwei单位) system.