History (1970s)
1970: ARPAnet spans US (total: ~10 nodes)
1972: Email, ftp born (due to Dave Crocker )
1973: Bob Metcalfe at Xerox designs Ethernet
1974: Vint Cerf & Kahn build first version of TCP, ARPAnet routing is revised
1977-78: TCP split into TCP and IP
1980-83: ARPAnet splits into ARPAnet and MILNET, and offers software at low cost to universities. NSF invests in CSNET connecting computer science departments.