J.C.R. Licklider from MIT is an internet pioneer because of his early vision of a worldwide computer network even before it was built. The first recorded description of the social interactions that could be enabled through networking was a series of memos written by Licklider in 1962. At the end of the year he joined DARPA.
Later on packet switching theory is developed by Leonard Kleinrock. In 1965 Lawrence Roberts and Thomas Merrill connected computers and built the first computer network. They all become pioneers of internet with many people that are not mentioned here.
The first message sent through ARPANET, from Prof. Leonard Kleinrock’s office in UCLA to Standford University that has internet connection.