LexisNexis Academic will help you identify and locate the texts of relevant laws and court decisions.
In some cases, you may wish to interpret as primary sources texts that originally were created as scholarly secondary sources. For example, if you are investigating the eugenics movement in the United States in the early twentieth century, you could look at articles on the topic that were published in academic journals in the 1910s and 1920s.
The following titles in Primo Search offer collections of primary sources that may be relevant to your project.
This is only a sampling of the collections out there, just to get you started!