Why the Civil Rights Movement, other than the immediately obvious reason? It brings things full circle with Uhura and her first actor, the late Nichelle Nichols, who initially planned on leaving the original Star Trek after a single season. It was a discussion with Martin Luther King, Jr. that changed her mind; as a fan of the show, he called her “our image of where we’re going. You’re 300 years from now, and that means that’s where we are and it takes place now. Keep doing what you’re doing, you are our inspiration.” And when she told him about her plans to leave, he told her, “You don’t have a black role. You have an equal role.”

TIL MLK convinced Nichelle Nichols to stay on TOS.