You will probably want to use a book in the main collection to understand the life and times of the person or object you are exploring.
Use the library catalog.
Search by subject=name or person, or movement. Retrieve the book from the shelf or ReCAP, or read it online.
Some people do not have an entire book written about them. The 12-volume African American National Biography has detailed shorter biographies that may also be useful. It is shelved in the African American Studies Reading Room on the B floor of Firestone Library, at E185.6 .A4466 2013.