In 1980 Duke University graduate students Tom Truscott and Jim Ellis established USENET, one of the first computer network communications systems. Truscott and Ellis conceived USENET as a "poor man's ARPANET."
The first newsgroups seem to have been established virtually at the inception of USENET.
"The first newsgroups on Usenet, according to Truscott, were known as NET.xxxx and dept.xxxx. After Horton joined Usenet, he began feeding mailing lists from the ARPANET into Usenet. Mailing lists from the ARPANET fed into Usenet were identified as FA.xxxx newsgroups. Truscott notes that, "Only when ucbvax joined the net, did `fa' appear." Truscott explains that he didn't know about the ARPANET mailing lists until Horton joined Usenet.
" At first the Usenet community could only read these ARPANET mailing lists, but couldn't contribute to them. "It was a one-way gateway - ARPANET into Usenet only, done with recnews, as I recall," writes Horton. But at least it was possible for the Usenet community to follow the interesting discussions carried on via the ARPANET mailing lists during this early period of Usenet" (http://www.columbia.edu/~rh120/ch106.x10, accessed 01-16-2010).