Uhura
Remarkably little has been established about Uhura's background
(she doesn't even have a first name), although we speculate she was
born in 2239, which would have made her 27 at the time of the original
Star Trek's first season. This, too, matches the age of the actor
portraying the role. We last saw Uhura in 2293 in Star Trek VI:
The Undiscovered Countiy
2239: Born (conjecture).
2257: Enters Starfleet Academy (conjecture).
2261: Graduates Starfleet Academy (conjecture).