On Friday April 13, 1973, at 7:30 p.m. a dozen or so individuals met and voted to form a local chapter of the Cactus and Succulent Society of America (CSSA), Inc., a national organization.  It was decided to meet on the last Sunday of each month, from 2-4 p.m. The  invitation to prospective members reads: “Our programs and speakers will be selected to help the serious grower become more proficient and knowledgeable. Our only purpose will be to enable our members derive greater satisfaction and enjoyment from our fascinating hobby.”
The rest is, of course, history!
Read more about the early days in the following two compilations:

From the original 22 charter members of 1973, CACSS has grown to over 500 members.  We invite you to look through our website, enjoy our newsletters, and consider joining us!

Our CACSS purpose is:

The purpose of the Society shall be: (a) to learn how to grow and study cacti, other succulents and associated xerophytes, (b) to foster, disseminate and advance the knowledge and propagation of cacti and other succulents, (c) to promote interest in those plants among the members and the public at large, (d) to support conservation programs which protect cacti and other succulent plants and their habitats, (e) to support the Desert Botanical Garden of Phoenix, Arizona, and other organizations of similar purpose, (f) to hold public meetings for study, to which anyone interested in these plants is invited, and (g) to provide the opportunity and place to exhibit plants.