February 2004: Mark Zuckerberg starts Facebook as a sophomore at Harvard University.
March 2004: Facebook begins expansion to other colleges and universities.
June 2004: Facebook moves headquarters to Palo Alto, Calif.
September 2004: Facebook introduces the Wall, which allows people to write personal musings and other tidbits on profile pages. Lawsuit filed against Facebook claiming that Zuckerberg stole the idea for Facebook from a company co-founded by twins Cameron and Tyler Winklevoss and a third person at Harvard.
Text and Images: AP