Brand new Civ player, here.
I have had two different cities, in two different games, kind of implode in early/mid game...not enough food, I guess, to support them. Here's what I think is happening: Both times, they were specialist cities that created warriors, archers, swordsmen, etc., for other cities. Maybe this isn't a good idea, supporting units all over creation.
2 questions: Is this theory correct, or am I on the wrong track? (I won't way that I have city management down yet, but most of my cities seem to get along fine with the various improvements I make).
If this is my problem, it seems like there must be a way of assigning units to cities other than the city they were created it, so that support of the unit falls to the new city. Or do I really have to create each city's units in that city to avoid this problem?