The three documents, known as the Charters of Freedom, include the United States Constitution, The Bill of Rights, and the Declaration of Independence. These important texts can be studied more online by visiting the National Archives. High resolution downloads of the documents are available at https://www.archives.gov/founding-docs/downloads. 

The Constitution and many historical documents are available from the National Archive as eBooks using the SCRIBD app. Visit their website or your preferred app store for more information. Once downloaded search for Exploring the United States Constitution. For more information visit the National Archives at https://www.archives.gov/publications/ebooks/exploring-constitution.html .

Milestone documents from other pivotal moments in U.S. history can be found at https://www.archives.gov/milestone-documents/list .