I'm always amused by the fact that so many of my ancestors were born in Essex, Massachussetts, rather than that other Essex in England. Colchester, Massachussetts, no less!
(now I've said that there probably *is* a Colchester in Massachussetts, but you know what I mean!).
I've found similar entries on Ancestry trees. I think it's something to do with Family Tree Maker which gives suggestions for places when you make an entry and you don't notice. I've done it myself a couple of times until I learnt to check my entries carefully.