ABC No Rio began in 1980 when the Real Estate Show, sponsored by Collaborative Projects, was "relocated" from an occupied storefront at 123 Delancey Street to 156 Rivington Street. In 2006 the latest group of people running the ABC No Rio succeeded in acquiring the building from the City of New York.

This is the website of the contemporary cultural center, ABC No Rio website.
That site includes a page of articles about the Real Estate Show, ABC No Rio, and related events and ideas.
The early history of ABC No Rio from the 1985 catalogue edited by Alan Moore and Marc Miller, discusses the place in terms of the art scene of the 1980s.
That catalogue was posted in a somewhat abridged form in 2010 by Marc Miller at: ABC the Book

In November of 2009, the Center for Puerto Rican Studies organized a conference at Clemente Soto Velez Cultural Center, right up (or down) the street from ABC No Rio. Alan Moore gave a paper at the conference, which was entitled "Re-Membering Loisaida." Here it is.