In an effort to deal with an increasing number of immigrants, in 1892 the U.S. government either banned or put limitations on many potential immigrants coming from Europe and Asia, especially China.
It was a kind of social protest - people did not want to be discriminated because of their race or sex. This event was a precedence - nobody thought that something like this protest could occur at that time. Rosa Parks did something that made people think about tolerance and also made other people join her protest in different places.
The excerpt above is part of the 14th amendment. This amendment was passed in 1868 and was supposed to help protect newly freed slaves. The goal in passing this was to ensure that African-Americans had the same legal rights as white citizens.
This due process clause has been used in several important Supreme Court cases to protect American citizens.
