A 19-year-old Harvard sophomore switched on a website restricted to fellow students, letting them post profiles and connect with classmates. Within 24 hours, over a thousand Harvard students had signed up, and within a month the site had spread to other Ivy League campuses, beginning a trajectory that would eventually reach billions of users worldwide as Facebook.
Mark Zuckerberg wrote the code for Thefacebook.com in his Harvard dormitory room, drawing on earlier campus projects like Coursematch and the controversial Facemash, a site that let students rate classmates' attractiveness and had gotten him hauled before the university's disciplinary board. The new site was simpler and less inflammatory: a directory where Harvard students could create profiles, list their interests, and see who else was in their classes.
Zuckerberg launched it on February 4, 2004, with help from roommates and friends including Eduardo Saverin, Dustin Moskovitz, and Chris Hughes. Membership was initially restricted by university email address, which created an aura of exclusivity and trust that distinguished it from the wide-open, often seedy social networks like Friendster and MySpace that preceded it. Within two weeks, roughly half of Harvard's undergraduate population had joined.
The platform expanded to Stanford, Columbia, and Yale within a month, then to universities across the country, before opening to high schools and eventually anyone over thirteen in 2006. What began as a way to check whether a crush was single grew into a company that would reshape advertising, journalism, political campaigns, and the very architecture of human social connection—along with a legal battle over its founding that became the subject of the film The Social Network and a reported settlement with the Winklevoss twins, who claimed Zuckerberg stole their idea.
Key people: Mark Zuckerberg, Eduardo Saverin, Dustin Moskovitz