The Chinese Exclusion Act was a U.S. federal law enacted in 1882 that prohibited Chinese laborers from immigrating to the United States. It was the first significant law to restrict immigration based on nationality and was a response to growing anti-Chinese sentiment during the late 19th century. The act aimed to limit the number of Chinese workers who were seen as competition for jobs. The law was initially set to last for ten years but was extended multiple times and made permanent in 1902. It was not repealed until 1943, during World War II, when the U.S. sought to strengthen ties with China against Japan. The act had lasting effects on Chinese communities in America and shaped immigration policies for decades.