Starting with the California Gold Rush in the late 19th century, the United Statesparticularly the West Coast statesimported large numbers of Chinese migrant laborers. Early Chinese immigrants worked as gold miners, and later on large labor projects, such as the building of the First Transcontinental Railroad. Chinese migrant workers encountered considerable prejudice in the United States, especially by the people who occupied the lower layers in white society, because Chinese 'coolies' were used as a scapegoat for depressed wage levels by politicians and labor leaders. In the 1870s and 1880s various legal discriminatory measures were taken against the Chinese. These laws, in particular the Chinese Exclusion Act of 1882, were aimed at restricting further immigration from China. The laws were later repealed by the Chinese Exclusion Repeal Act of 1943.