The Chinese Exclusion Act of 1882 was a United States federal law signed by President Chester A. Arthur on May 6, 1882, prohibiting all immigration of Chinese laborers for 10 years. The law made exceptions for travelers and diplomats. The Act also denied Chinese residents already in the US the ability to become citizens and Chinese people traveling in or out of the country were required to carry a certificate identifying their status or risk deportation. It was the first major US law implemented to prevent all members of a specific national group from immigrating to the United States, and therefore significantly shaped twentieth-century immigration policy.