Books are shelved in general subject categories using the Library of Congress classification system. You may want to supplement your use of the catalog book search with browsing shelf areas for your topic.
Books on 1960s and early 1970s history are shelved on the library's upper level generally from E 838 through about E 861. Information concerning the topics of Civil Rights and African-Americans can be found in E 184.5 through E 185.98.
Image from: Palmerston North City Library
To find primary source materials available in the Gustavus library, go to the Advanced Search in the library catalog. In one of the search boxes, enter the word "source" and set the field to "Subject." Then, enter keywords related to your topic in another box. This search will bring back primary source materials that are in edited volumes.