Following are some sources of information on the ideas behind the founding of our nation and how we became "America".



The Tenth Amendment Center is an excellent source of background and articles that explain the source of founding ideas and how they fare today.   

https://tenthamendmentcenter.com/

If you need to be able to get into the Constitution quickly and be able to discern which parts of the original have been affected by admendments it is hard to beat the site offered by the National Archives.

https://www.archives.gov/founding-docs/constitution-transcript