The population growth in the Chicago suburbs has shifted from Naperville (in the 1980s and 1990s) to communities further west and south. In particular, Aurora grew during the 2000s and is now Illinois’ second largest city:

[T]he Alperins are among the nearly 55,000 new residents since 2000 who helped Aurora boost its population to 197,899 and officially eclipse Rockford as Illinois’ second-largest city, according to the recently released 2010 U.S. census figures.

Aurora’s 54,909 jump was the largest among Illinois cities. Its percentage increase of 38.4 percent was just behind top-ranked Joliet, which grew at a 38.8 percent pace to 147,433 and beat out Naperville as Illinois’ fourth-largest community.

The growth comes as Aurora makes strides resurrecting what had become a struggling downtown and boasts of statistics that show the city’s major crime rate is at its lowest in more than three decades. The physical size of the city also has grown to accommodate more people. Aurora has three times as many square miles as it had four decades ago.

There are several reasons that the community has grown including a growing Hispanic population and open land in a growing region of the Chicago suburbs. But the city has also dramatically expanded in size:

Aurora, meanwhile, now covers 46 square miles compared with 35 in 1990 and 15 in 1970. It sprawls through four counties, six school districts and seven townships. But like Naperville in the last decade, the city could eventually be boxed in by neighbors, Greene said. And there’s also no guarantee that brisk growth from the 1990s through part of the 2000s will repeat when the economy improves.

The explanation for why Aurora is growing is very similar to what led to Naperville’s growth between 1960 and 2000: it is located near highways, it has a number of businesses, and there is plenty of room to expand and the city has annexed a lot of land. But as Naperville discovered, the growth only goes on for so long: eventually, the land runs out and then Aurora will become a different kind of place. As the end of the article notes, the long-term course of the city will likely include denser development near the center of the city.

At the same time, Naperville and Aurora’s growth are not quite the same: Naperville has long had a wealthier profile compared to Aurora’s status as an industrial satellite city (named as such in this 1915 work).  During the 1980s and 1990s, Naperville’s growth was quite unusual: Naperville was classified as the only boomburb outside of the South or West during the last two decades of the twentieth century. Naperville is quite well-off for a large community, has a history of high-tech companies dating back to the mid-1960s, has very low crime and poverty rates, and has a vibrant and popular downtown.

It will be interesting to watch in the coming years how Aurora, Joliet, Plainfield, and other suburbs in the southwest suburbs continue to grow.