People in London, who live in the suburbs, may tell you they work 'up town', meaning in the City or the West End.
In other large cities in Britain, Birmingham, Manchester, Leeds etc., I think people who earn their living in the City Centre (equivalent to Downtown with capital D) will say casually that they work 'in town'. I think I'm right when I say that only Londoners go 'up town'.
So where did the idea of 'Downtown' come from?
Best Answer
Citing Downtown: Its Rise and Fall, 1880-1950 by Robert M. Fogelson, Wikipedia says: