This envelope is particularly interesting from a postal history point of view. The writer, Dr. Roberta G. Rice, was writing to Dr. Charles Mayo the head of the renowned Mayo Clinic, and his wife in a personal capacity. Dr. Rice was a member of the (American) Methodist Mission who had been appointed after the Korean War to serve as a medical educational missionary.
Roberta Geraldine Rice was born in 1917 in LeSueur Center, Minnesota, the daughter of a Methodist minister. She graduated from the University of Minnesota Medical School when there were still many barriers to women in medicine. She completed an internship at the University of Illinois and received surgical training at the Mayo Clinic under her mentor Dr. Charles Mayo.