The American Homebrew Association is the organization representing homebrewers nationwide, it is an arm of the Brewers Association. It has been around since 1978 and was founded by homebrew founder Charlie Papazian.
One of the many things the AHA does is advocate nationally for homebrew friendly laws. The AHA also holds the largest beer tasting in the world. Members get discounts nationwide as well as first dibs on GABF tickets. Zymurgy, a magazine for homebrewers, is included with membership.