Community Memory was the first public-access social media system, opening without advance notice on August 8, 1973 in Berkeley, California. Designed and programmed by members of a nonprofit company established to bring the power of computers to the counterculture, it ran on a mainframe computer and was well received by those who tried it. This chapter discusses the history of the project, contributions of some of its members, and ways in which it succeeded and ultimately failed to sustain itself. Pre-dating the personal computer, it was designed to provide terminals that nucleated neighborhood information-exchange points. Community Memory spun out from its parent organization, Resource One, Inc. to form its own nonprofit -- The Community Memory Project -- in 1977. The design underwent three generations, culminating in a network of text-based browsers running on basic IBM PCs accessing a Unix server. It was never connected to the Internet, and closed in 1992. — Judy Malloy, Social Media Archeology and Poetics