Use the search box called "Find Articles & More" (scroll to next box below to find it) to look for a "Research Starter" through Sprague Library. Do NOT limit to peer-reviewed sources since background sources such as encyclopedia entries are not usually peer-reviewed.
Here's a captured image of what a Research Starter looks like.
Search in an encyclopedia or in a database such as CQ researcher for a shorter article that provides basic information (history, context, facts) about your act/policy.