Correspondence and writings of Six Major Shapers of the United States: George Washington, Benjamin Franklin, John Adams (and family), Thomas Jefferson, Alexander Hamilton, and James Madison.
Cornerstone Documents of U.S. democracy - including:
Documents in Law, History and Diplomacy -- not only US documents (has Code of Hammurabi and Communist Manifesto for example) - searchable or click on number; state charters, etc. (Avalon Project at Yale Law School)
100 Milestone Documents - highlight key events in U.S. history (1776-1965), each document includes an image, description and transcript. (NARA)