Another movie of the "Guess Who's Coming to Dinner" era that comes to mind is "Gentlemen's Agreement" starring Gregory Peck. In that film, Peck portrays a writer who tells people he's Jewish for a series of articles about his experiences with bigotry, discrimination and stereotyping. Even his young son is taunted by classmates and his girfriend, who considers herself open-minded, is forced to take a good look at her own deep-seated prejudice.

The original Star Trek was a groundbreaking TV show on more levels than have been mentioned here thus far. TV's first interracial kiss was planted on Nichelle Nichols by William Shatner, in the episode "Plato's Stepchildren". Then there was the episode "Let That Be Your Last Battlefield", in which two aliens aboard the Enterprise are calk-white on one side and jet-black on the other but consider themselves to be of different races ("Isn't it obvious? Lokai is white on the right side. All his people are white on the right side."). One "race" has enslaved the other, and their determination to exterminate one another threatens the ship and destroys their planet. Of course, there was also the ongoing theme of Spock's mixed-race status (half-human, half-Vulcan) and the various ways it affected his life, including frequent verbal attacks by the ship's doctor.

But robomatic's citing of Bonanza confuses me. I didn't watch the show, so I'm unfamiliar with any role it might have had in changing viewers' attitudes about racism. Robo, please enlighten me!