When I was a teacher the name of Dr. Martin Luther King, Jr. must have flew out of my mouth at least once a day. He was such a hero in the eyes of the kids in my class that almost all discipline issues could be addressed simply by invoking his memory.
I never had to teach it. My first graders would usually come in with a good understanding of what he would expect in terms of their behavior and classroom performance. Those who didn't get it would get schooled on the facts but good by their classmates. He was better than Santa Claus no matter what color, size or shape the kid was. I know it's a minor point in the man's legacy but I'm forever grateful to him for making my job easier.