Jim Jones cult leader and founder of the People's Temple during the 1950's in Indiana. Jones then moved his followers to California in the 1960's and gained some notoriety in San Francisco. From there he moved his followers from the United States to Jonestown, Guyana. 
Jones committed suicide while his followers drank a poisoned kool aid killing 918 people on November 18, 1978. 

Vintage People's Temple medical services authentic unused envelope.