Interesting error on the Wikipedia page for Star Trek: The Original Series:
Star Trek is a science fiction television series created by Gene Roddenberry that aired on NBC from September 8, 1966, to June 3, 1969.
The show actually ended on March 14, 1969. A final episode, "Turnabout Intruder," was shown in the summer reruns of 1969 (that's where they got the June 3 date). Wikipedia makes it sound like the show ran into extra innings--it's not baseball. Someone should correct this blooper.