What were once distinct and separate cities and regions have grown into one another due to metropolitan expansion, and they now compete for land, businesses, houses and loyalties in a way they didn’t before. The same processes­ that turned the Northeast Corridor into America’s first megalopolis are also at work in Philadelphia itself, changing it into a metropolis that might be absorbing its neighbors.

Anne Mosher, associate professor of geography and the environment, says this sort of blending is happening throughout the Northeast megalopolis. “What all of this adds up to is a really complicated rewiring of activity patterns where people who live in the hinterland have greater choice as to which big city they gravitate toward for employment/shopping/sports-team fandom, where they can more easily travel to the big city they find most appealing, thus making areas around places like Allentown, Carlisle, York and Scranton into urban-rivalry free-for-alls,” she says.

Read more in the Philadelphia Magazine article, “The Philly Suburbs Are Bigger Than Ever — Literally.”