Currently, the fair is held annually at the Illinois State Fairgrounds over an 11-day period in mid-August of each year.

[2] The 1850s were a golden age of agricultural journalism, with a wide variety of editors offering many suggestions, well-founded or not, to increase farm productivity.

During the years after the Civil War, the rules of agricultural judging became standardized, and more and more farmers began to show their farm products.

In the first half of the 20th century, the internal combustion engine revolutionized life on the American farm, with manufacturers of agricultural machinery eagerly taking advantage of occasions like the Illinois State Fair to demonstrate their new products.

In 1893, for example, the organizers of the World's Columbian Exposition in Chicago prepared to offer a larger lineup of agricultural products and machinery, so the Illinois State Fair canceled itself for one year.

In Illinois, the State Fair Grandstand, originally built as a place to watch harness racing (and still used for that purpose as of 2022) became a venue for concerts and recitals.

The "state fair circuit" became a recognized part of the overall live-music industry for many performers, especially but not exclusively in country music.

"[4] The Illinois State Fairgrounds are also used as a venue for other competitive and entertainment operations throughout the year, such as motorcycle and car racing, horse shows, and rodeos.

[10] The 2020 state fair was reduced as a safety measure during the COVID-19 pandemic in Illinois, the main shows were removed, the first cancellation since World War II.

The Illinois State Fair was featured on the NBC-TV show The Great American Road Trip in July 2009.