Gruber was one of the founding members of the Mattachine Society, a homophile organization. The papers contain letters, clipped news items, draft writings and photographs.
![[Stan Witt at Nevada Club of Las Vegas]](https://digitalsf.org/sites/default/files/styles/enhanced_grid_small/public/externals/bcb81a9b007bc9a317620599ecd51988.jpg?itok=vvOWwBEp&pid=islandora:155206&iic=true)
