From 1882 to 1943 the United States Government severely curtailed immigration from China to the United States. This Federal policy resulted from concern over the large numbers of Chinese who had come to the United States in response to the need for inexpensive labor, especially for construction of the transcontinental railroad. Competition with American workers and a growing nativism brought pressure for restrictive action, which began with the Act of May 6, 1882 (22 Stat. 58). Passed by the 47th Congress, this law suspended immigration of Chinese laborers for ten years; permitted those Chinese in the United States as of November 17, 1880, to stay, travel abroad, and return; prohibited the naturalization of Chinese; and created the Section 6 exempt status for teachers, students, merchants, and travelers. These exempt classes would be admitted upon presentation of a certificate from the Chinese government.