Here are some possible search terms and variations. This list isn't intended to be definitive but simply to give examples.
African American, African Americans, Black race, Civil Rights, Hate Crimes, Jim Crow, Prejudices, Racial profiling, Racism, Segregation, Slavery
When doing research on the web it is really important to evaluate the source. There are many different methods of deciding if a source is credible, an easy evaluation phrase to remember is The CRAAP Test:
timeliness of the information
importance of the information for your needs
source of the information
reliability, truthfulness, and correctness of the content
reason the information exists