All of the sources below can be used to help you explore a topic and get general background information. Many articles will have extensive bibliographies; you can use these to find additional sources.
Unidentified African American Union soldier with rifle & revolver before painted backdrop showing weapons & American flag, Benton Barracks, Saint Louis, MO - Qtr-plate, hand-colored tintype. Liljenquist Family Collection, Prints & Photographs Division, Library of Congress [Digital ID # ppmsca-36456]
Did you know UW Libraries provides current UW and Cascadia students, faculty, and staff with direct access to the New York Times website and more? Once you set up your account, you can go directly to the newspapers' sites to read their articles and avoid encountering paywalls.
Each of these databases has scholarly sources (that is, peer reviewed articles) you can use in your research. Please be aware that not everything in each database is scholarly, however. If you need help identifying scholarly articles, ask a librarian! https://library.uwb.edu/askus