The Government Printing Office has a host of information for you. Government Printing Office which provides electronic access to Federal Government documents. The site gives you access to official, published versions of legislative, executive and judicial documents, including the Code of Federal Regulations, Federal Register, and Presidential Materials.
For example, do you need an analysis of cases interpreting the U. S. Constitution? There is a publication on point. There is even a Cybercemetary, where old government websites are maintained.