Aurora is the second most populous city in the U.S. state of Illinois, and the 111th largest city in the United States. The population in 2010 was 197,899.
Once a mid-sized manufacturing city, Aurora has grown tremendously due to urban sprawl over the past 50 years. Originally founded within Kane County, Aurora's city limits and population now spill over into DuPage, Will and Kendall counties. Between 2000 and 2003, the U.S. Census Bureau ranked Aurora as the 34th fastest growing city in the United States. From 2000 to 2009, the U.S. Census Bureau ranked the city as the 46th fastest growing city with a population of over 100,000.
In 1908, Aurora officially adopted the nickname "City of Lights", because it was one of the first cities in the United States to implement an all-electric street lighting system in 1881. Aurora's downtown is located on the Fox River. The historic downtown is centered on Stolp Island. The city is divided into three regions, The West Side, located on the west side of the Fox River, The East Side, located between the eastern bank of the Fox River and the Kane/DuPage County line, and the Far East Side/Fox Valley, which is from the County Line to the city's eastern border with Naperville.