1970's - Used by the U.S. military, U.S. defense contractors, and universities doing U.S. defense research

early 1980's - split into ARPANET and Milnet -- the connection between these two networks was called the DARPA Internet or the Internet

1980's - NSFNET (National Science Foundation Network) created its own regional based network

1986 - NSFNET began replacing ARPANET and connecting mid-level and state-level university networks

late 1980's - other countries began to connect to the Internet (U.K., Australia, Japan,...)

1990 - ARPANET sent its last packet