Kevin's grandmother received this rejection letter from Walt Disney Productions in 1938, telling her that she wasn't welcome at animator training school because she was a girl. The sting seems to have been mitigated somewhat by the excellent stationery they sent the note on. Link (Thanks, Kevin!)
Update: Glen sez, "This guy blogged about the Disney Studios Artist's Tryout Book that was released in 1938: 'All inking and painting of celluloids, and all tracing done in the Studio is perfomed exclusively by a large staff of girls known as Inkers and Painters... This is the only department in the Disney Studio open to women artists.'"
Update 2: danah boyd sez, "During my sophomore year at Brown (1997), I attended SIGGRAPH. There was an Imagineering booth where Disney was doing recruiting. I approached and asked if there were internships available, but the recruiter told me that there were no internships available for artists. I responded by saying that I was a developer and that I wanted to code. The response I received was, 'but you're a girl.'
"I walked away stunned and midway out of the convention hall, I ran into my advisor (Andy van Dam) and relayed this story. He turned beet red and ran off to 'make things right.' Not 15 minutes later, I saw the recruiter at Disney stomping out of the hall. I found out later he was fired. "