The Avalon Project is a repository of digital documents and includes the Federalist Papers and documents from the Continental Congress, and much more.

Primary sources collection contains 2 parts:
Part I. Primary sources, 1620-1926 -
Part II. Primary sources, 1763-1970
Contains a virtual goldmine of information for researchers of American legal history, including a fully searchable digital archive of the published records of the American colonies, documents published by state constitutional conventions, law dictionaries, digests, and more. [Publisher's note]

Includes full text of current and historical United States state constitutions. Also includes the Oxford Commentaries on the State Constitutions of the US series, which offers article-by-article commentaries on most states' constitutions and their historical development.

Collection of the constitutions of the 50 states of the United States, together with related documents and resources. Contains the text of every constitution that has been in force for every state.

Current constitutions for every country in the original language along with at least one English translation. Includes expert commentary, the complete set of the British and Foreign State Papers, and other significant Sources such as Country Studies, the World Fact Book, and Annual Human Rights Reports Submitted to Congress by the U.S. Department of State.

Includes an excellent libguide that links to numerous additional resources across academia, the federal government, and various constitution projects.