Link: Pittsburgh Then and Now

So Pittsburgh used to be a black(ened) city before it put in place air pollution regulations, following the model of Saint Louis. [io9 has a nice collection of photographs ](http://io9.com/5915418/before-environmental-regulations-pittsburgh-looked-like-the-capital-of-hell)and then a series of comments from Burghers who live there now or wish they lived there now. Apparently, Pittsburgh has transformed itself into a modern, green city with just enough going on to make it a really pleasant place to live — but not so much going on that it’s over-run by hipsters.