This list is not exhaustive - if you search terms like Africa, encyclopedia, and your component, such as history, art, culture, politics, geography, and so on, there will likely be a resource that can help in some way with your research.
The following is a select list of Library of Congress (LC) Subject Headings that may be helpful in finding information: You can simply type them into the catalog or enter them as a subject search.
The way to discover these terms is to search your city, click on a resource, and look at the list of subject terms that come up - this is an easy way to discover keywords to search.