University of Pennsylvania
University of Pennsylvania: The Illuminati
Basic information about the Illuminati and its founder, Adam Weishaupt.
Other
Encyclopedia.com: The Illuminati
Explains what the Illuminati is, how it was formed, its attempt to infiltrate and take over the Freemasons, and its condemnation by the Bavarian monarch in 1787.
University of Virginia
University of Virginia: History of the Illuminati
A short history of the Illuminati.
Other
Bavarian Illuminati: The Historical Bavarian Illuminati
A history of the Illuminati from its first roots in Bavaria.