The Karpeles Library Manuscript Museum is the "the world's largest private holding of important original manuscripts & documents." Some of the more interesting include:

• The Bill of Rights: The original draft, in searchable form, of the Bill of Rights
• Einstein's Theory of Relativity: Einstein's original document describing his famous theory
• Handel's Messiah in Beethoven's Writing: Just gorgeous - ink blots and all.

The best way to search this site is to view the manuscripts and documents alphabetically first; that way, you can get an idea of what the museum has to offer.

Related: Looking for more documents and manuscripts online? Search the Deep Web with CompletePlanet, a Deep Web search engine, or take a look at my Arts and Humanities Resources on the Invisible Web.