2.3.2State of Illinois prior to the Civil War. 2.3.3Civil War and after. 2.420th century. Illinois: The history and demographics of the Prairie State Learn more about Illinois and its geography, people, economy, and history. Illinois, constituent state of the United States of America. It stretches southward 385 miles (620 km) from the Wisconsin border in the north to Cairo in the south. Search through all the different services offered by the various Illinois agencies. During live broadcasts use the links below to tune in to audio and video feeds for the latest coverage from the State of Illinois. Governor JB Pritzker and the Illinois Department of Revenue (IDOR) have announced disaster tax relief for individuals and businesses in 15 counties impacted by severe storms in May through August 2026. With Illinois Lottery, Anything's Possible with games like Mega Millions, Powerball, Lotto and Lucky Day Lotto. Buy tickets online and find winning lottery numbers! Lobbyist Information Search Find lobbyists and lobbying groups registered in Illinois. Statement of Economic Interest Search Access statements filed by state employees and elected officials. Inspector General’s Office File a complaint, review statistical and published reports, and more. What does the abbreviation IL stand for? Meaning: Illinois. How to use IL in a sentence. From urban excitement and outdoor adventures to delicious food and fascinating history, Illinois is an iconic destination with something for everyone. Scroll through the regions to explore the diversity of experiences in the Middle of Everything. There are 102 counties in Illinois. The most populous of these is Cook County, the second-most populous county in the United States and the home of Chicago, while the least populous is Hardin County. The largest by land area is McLean County, while the smallest is Putnam County. Illinois's FIPS state code is 17 and its postal abbreviation is IL. Illinois has been nicknamed as “The Prairie State” in reference to the landscape of rolling hills and prairies that occupy large areas of the state. Physical map of Illinois showing major cities, terrain, national parks, rivers, and surrounding countries with international borders and outline maps. Key facts about Illinois.