The primary reason for the Chinese Exclusion Act of 1882 was the increasing anti-Chinese sentiment in the United States. During the 19th century, Chinese immigrants were often scapegoated for economic troubles and were seen as a threat to American jobs and culture. The Act was the first law to officially restrict immigration based on nationality and was driven by labor competition fears and racial prejudice. It effectively barred Chinese laborers from entering the U.S. and set a precedent for future immigration restrictions based on race and nationality.