Engineer Olson, first redshirt to die in the reboot. Memory Alpha notes that he’s from England, and spoke with a Northern (Manchester-Lancashire accent).
However, “Lots of planets have a North”.
I vaguely recall that, by the time we actually meet Worf’s adoptive parents, they’re living in St. Petersburg, though of course that doesn’t mean Worf himself ever lived there.
Well, we don’t know that this is entirely true. It’s possible that the former nation-states still exist as distinct administrative divisions with a measure of self-government; the fact that we have a “United Federation of Planets” suggests that the founders of the united Earth government weren’t averse to federalism as a governing philosophy.
It’s likely, in fact, since at the very least Vulcan, Andoria, and Tellar Prime (3 of the four founding worlds - the other being Earth) have ambassadors to the Federation, at least as of TOS (and they’re pretty hostile toward each other).
Memory Alpha’s article on the Federation describes it as:
“With 46 appearances, Nog was the most frequent recurring character on Deep Space Nine.” (Memory Alpha).
Geeky, moi? 
If ya wanna throw in the MOVIES, I absolutely loved Persis Khambatta as Lt Ilia in ST:TMP.
(don’t remember what species Ilia was…)
I was heartbroken to read that she passed away in 1998.
~VOW
<geek>Deltan</geek>
Well, that page is wrong. According to the same website Morn appeared 92 times, and Quark’s waiter Broik 72 times.
I think Morn falls more under the category of “set”, rather than “cast”
