Stallman admits that the "movement" was common practice at MIT by the time he got there. In the acadamic world software was shared with those who asked for it, and re-shared, and re-shared. What set him off was when they got a PDP and he was suddenly told he had to sign an NDA and couldn't share anything anymore. So he just started writing his own OS, the beginning of GNU, thus the "free software movement" as you know it.
Really what the GPL/GNU/FSF tries to do is recreate the rules that the old hacker community lived by before Stallman even joined it.
From Wikipedia, the "open source encyclopedia", again all very straightforward, except for those seemingly attempting to cover it all up:
http://en.wikipedia.org/wiki/Richard_Stallman
Richard Matthew Stallman (frequently abbreviated to RMS) (born March 16, 1953) is the founder of the free software movement, the GNU project, and the Free Software Foundation. An acclaimed programmer, his major accomplishments include Emacs (and the later GNU Emacs), the GNU C Compiler, and the GNU Debugger. He is also the author of the GNU General Public License (GNU GPL or GPL), the most widely-used free software license, which pioneered the concept of the copyleft.