Take the time to think about your topic and find resources to help you better define it. Searching for "the Civil War" is too broad, but it can be your starting point to finding a specific person, battle, or group of people you want to learn more about. When you do this background information searching it will be easier to create your research questions.
Use a timeline to get a perspective on your topic:
You can use on of the library's databases of Reference Sources to find some helpful background information for your general topic:
Online encyclopedia of African-American history.
Features thousands of cross-referenced entries, covering the entire spectrum of African-American history over the past 500 years.