3420 Boelter Hall, UCLA

45 years ago today (September 2, 1969), at the University of California in Los Angeles (UCLA), the first Interface Message Processor (IMP), built by BBN, is connected for the first time to its SDS Sigma-7 mainframe, thus establishing the first node of what will become the ARPANET (and later, the Internet), the first wide-area packet switching network. 

“We cautiously connected and the bits began to flow.

The pieces really functioned, just why I still don’t know.

Messages were moving pretty well by Wednesday morn.

All the rest is history. Packet switching had been born.”

–Leonard Kleinrock on the day the first ARPAnet IMP was connected to the mainframe at UCLA, quoted in Stephen Segaller, Nerds 2.0.1, 1998

The photo above is of 3420 Boelter Hall at UCLA, where the IMP was installed, today serving as a small museum marking the beginning of the history of the Internet. See This Is The Room Where The Internet Was Born