Below are links to use when researching race relations in the context of the novel To Kill a Mockingbird:
Library of Congress Civil Rights Primary Sources
Smithsonian Institution Segregated America Collection
http://www.sweetsearch.com/
http://www.infotrek.info/
http://www.history.com/
https://commons.wikimedia.org/wiki/Main_Page
https://pixabay.com/
http://www.everystockphoto.com/