You don't have to look at the buildings or the people in Washington, D.C.'s historically black Petworth neighborhood to see that things have changed. Some say you just need to look at the dogs. "It used to be nothing but pit bulls and Rottweilers around here," says a longtime resident who gives his name as Lattimore Jenkins. He sits on a blue cooler across from a new condominium building. "Now you got them little baby dogs, Jack Russells, Chihuahuas."

The community has undergone other changes, of course. The tony apartments squatting over the Petworth Metro station where a vacant lot used to be. The bright red bikes, available to rent, lined up along a rack on the corner. The organic supermarket down the street from a decaying Safeway.

Dave Weigel makes a point no one should ever forget: