The history of Chinese Americans or the history of ethnic Chinese in the United States relates to the three major waves of Chinese immigration to the United States with the first beginning in the 19th century. Chinese immigrants in the 19th century worked as laborers, particularly on the transcontinental railroad, such as the Central Pacific Railroad. They also worked as laborers in the mining industry, and suffered racial discrimination at every level of society. While industrial employers were eager to get this new and cheap labor, the ordinary white public was stirred to anger by the presence of this "yellow peril". Despite the provisions for equal treatment of Chinese immigrants in the 1868 Burlingame Treaty, political and labor organizations rallied against the immigration of what they regarded as a degraded race and "cheap Chinese labor". Newspapers condemned the policies of employers, and even church leaders denounced the entrance of these aliens into what was regarded as a land for whites only. So hostile was the opposition that in 1882 the United States Congress eventually passed the Chinese Exclusion Act, which prohibited immigration from China for the next ten years. This law was then extended by the Geary Act in 1892. The Chinese Exclusion Act was the only U.S. law ever to prevent immigration and naturalization on the basis of race. These laws not only prevented new immigration but also brought additional suffering as they prevented the reunion of the families of thousands of Chinese men already living in the United States (that is, men who had left China without their wives and children); anti-miscegenation laws in many states prohibited Chinese men from marrying white women.