The Fourteenth Amendment, which guaranteed citizenship and equal protection under the law, was designed to protect the rights of newly freed African Americans following the Civil War. Later, other groups, such as Mexican Americans and Asian Americans, cited the Fourteenth Amendment in important court cases to argue for their right to equal protection under the law.
This law says that people who were not white and not Christian could be made slaves. It also says these people were "real estate," that is, property. This shows that the United States had chattel slavery, and that this slavery was based on race and religion.
American Indians are called "indigenous peoples," meaning they belong to the continent of North America. Historians estimate that American Indians have been living in North America for at least 15,000 years.
When the Mexican American War ended in 1848, Mexicans who lived in the conquered territories that became Texas and the Southwest United States became U.S. citizens, but not by choice. The Treaty of Guadalupe Hidalgo guaranteed these involuntary immigrants citizenship. It also promised to honor their land claims, although this was seldom done.