Another Mary...were ALL the women then named Mary?
looking it up...OK so that letter is dated '38. But...
"Both Blairs soon began to work in the animation industry, joining the Ub Iwerks studio. Lee went on to work at the Harman-Ising studios before ultimately joining the Walt Disney studio where he was joined by his wife in 1940."
"After leaving the studio for a brief time in 1941, Mary traveled to various South American countries with Walt and Lillian Disney and other artists on a research tour as part of President Franklin D. Roosevelt's Good Neighbor policy. During those trips, Mary and Lee worked on concept art for the animated feature films Saludos Amigos and The Three Caballeros with Mary credited as art supervisor on those films."
I surely do hope that the recipient of that letter, Mary Ford, applied, b/c it looks like only a couple years later they had opened things up to women!