ARPANET originally connected the US Department of Defense researchers to This network originally consisted of four universities including the University of California at Santa Barbara, the University of California at Los Angeles, the Univresity of Utah, and the Stanford Research Institute. Only the military, contractors and universities that were doing research for the Department of Defense could have access to this network.

This network was so successful that after two years, more than twenty sites had been connected. Within the next ten years over 200 sites had been connected. In addition, entire networks were being connected to this network which was now called the Internet.