To gather background information, yes, you sure can (with some caveats).
Wikipedia articles are often written and monitored by scholars, librarians, committed amateur researchers, and others who are vested in providing free and reliable information. Unlike print encyclopedias, Wikipedia can be updated and/or corrected faster than text going through traditional publishing avenues. Better articles also have plenty of sources you can use to validate the facts you find in the article and explore for further information.
However, Wikipedia articles can also be created or edited by anyone, at any time. Errors are often caught quickly, but there is no formal review process in the same way there is with a traditional encyclopedia. The same article could change day to day.
Instead, use Wikipedia to learn more about your topic and get ideas for further research.
You can use a variety of types of reference sources to help you define unknown terms, place the issue in historical context, learn about the major people involved, and more. You may or may not put all the information you find in your final paper.
Sources you may want to use:
Use the resources linked below or browse for print reference texts on Level 3 of the Thomas Jefferson library. You can also often find some reference texts linked on the library's online subject guides.
Biography Reference Source offers a collection of more than 461,000 full-text biographies, including the complete full-text run of Biography Today and Biography.