Illinois is the 5th most populated state in the country and with Chicago in the Northeastern corner there is a wealth of job opportunities and internships in Illinois. Because of its size, Illinois offers a variety of internships ranging from agriculture internships (a lot of the state outside of Chicago is farmland) to finance internships and sports internships with prestigious teams such as the Chicago Cubs and Chicago Blackhawks. Illinois is also the 4th largest manufacturing state, with a huge manufacturing industry in the northeast in and around Chicago. Lastly, Chicago has an incredible arts and museum scene for those interested in arts internships.
Summer internships in and round Chicago are extremely popular as summer interns can enjoy mild weather, access to the Great Lakes and an extremely vibrant Midwestern city. That said, the state is a great place for full-time jobs as well.