Martin Luther King Jr was a Star Trek fan; in fact, actress Nichelle Nichols, who played the character Lieutenant Uhura on the television series, was going to quit the show until King convinced her to stay. Nichols was considered to be symbolic of civil rights movement for portraying an African American woman in a leadership role on television.
King is said to have told Nichols that Star Trek was the only show he would let his children watch because it had racial diversity in its cast. After that 1967 meeting with King, Nichols went on to continue the role of Lieutenant Uhura on television until 1969, as well as for additional movies thereafter.
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