History from the Online University
Began in early 1960's by Defense Department (DARPA) - The goal was to develop a very robust network that could survive a nuclear war. That was actually a good strategy to plan for a worst case scenario, so today, if there is a problem on one part of the network, traffic will automatically route itself around the problem.
First computers connected in 1969 ARPANET (Stanford was one of the first sites)
Originally designed for e-mail, file sharing, remote login.... now handling WWW, Internet Phone, Internet TV.
The more folks who have a network connection, the more valuable the network becomes. Kinda like a phone or a FAX machine.