Illinois Population Up 3.3 Percent in 2010 Census
Illinois Remains 5th Largest State in Nation, Cook County Remains the 2nd Largest County in the Nation, Chicago Remains 3rd Largest City in the Nation
Illinois' 2010 census results show over 12.8 million (12,830,632) people live in Illinois, up 3.3 percent since 2000. The 2010 Census had the most massive participation effort ever experienced in the country with 74 percent of households voluntarily returning their census forms by mail. Illinois' 76 percent participation rate was above the national average and due in part to collaborations with community organizations to promote participation in the Census throughout the state.