The first message ever sent over what is now called the Internet took place at 10:30PM on October 29, 1969. Back then, the Department of Defense called it ARPAnet (Advanced Research Projects Agency network).
Alexander Graham Bell's notebook entry of 10 March 1876 describes his successful experiment with the telephone. Speaking through the instrument to his assistant, Thomas A. Watson, in the next room, Bell utters these famous first words, "Mr. Watson -- come here -- I want to see you".