Why did the us congress pass an exclusion act in 1882 barring chinese immigrants?

Chinese exclusion act was a law passed in 1882 to ban the Chinese laborers from immigrating to the US.  the law was first to ban the immigration of the entire ethnic group. It also barred Chinese from acquiring Chinese citizenship. In the initial act, it only barred laborers, but in 1924 it banned all Chinese nationals from immigrating. The main reason for banning the Chinese was the xenophobia caused due to the jobs being taken by Chinese. They wanted to prevent American society from Chinese migrants.