ARPANET

The Advanced Research Projects Agency Network (ARPANET) was the world's first operational packet switching network and the progenitor of what was to become the global Internet. The network was initially funded by the Advanced Research Projects Agency (ARPA, later DARPA) within the U.S. Department of Defense for use by its projects at universities and research laboratories in the US. The packet switching of the ARPANET was based on designs by British scientist Donald Davies and Lawrence Roberts of the Lincoln Laboratory.

Read more about ARPANET:  History, Software and Protocols