Don't know where to start? Try one of the following database portals. They allow researchers to search across multiple databases produced by the same publisher or archives.
The Library has a number of databases that contain primary source documenting the history of racial violence in America. Here's a list to get you started. It is strongly recommended, however, that you set up an appointment with your subject librarian, Erica Bruchko, for help navigating these databases and to identify additional collections.
Manuscript Materials (Plantation Records, Personal Papers, etc.)
Printed Materials (Books, Newspapers, and Magazines)
Slave Narratives
Municipal, State & Federal Government Records (Selected)