- Capital: Springfield, IL
- Largest City: Chicago, IL
- Area: 57,918 sq mi
- Rank: 25
- Population (2010): 12,830,632
- Rank: 5
- Admission to Union: December 3, 1818
- Time Zone: Central
"The citizens of Rockford had been so enthusiastic about their Forest Citys since the great upset win over the Nationals in 1867 that they were 'freely forking down their greenbacks to pay their players for the time spent in practicing'." - from the book When Johnny Came Sliding Home: The Post Civil War Baseball Boom, 1865-70
Illinois was an early hotbed of baseball. Some of the great early players such as Cap Anson and Al Spalding were involved in amateur and pro ball in Chicago, IL or Rockford, IL. The Excelsiors were the first amateur club in Chicago, founded even before the Civil War in 1858.
When the National Association got started in 1871, the Chicago White Stockings were one of the strongest teams, although the Great Chicago Fire was devastating to the team, forcing them to drop out of the circuit for the next two seasons. Rockford also fielded a team in 1871, with a 19-year-old Cap Anson at third base.
In 1876, the White Stockings won the pennant in the first year of the new National League.
Through 2010, over 1,000 major leaguers have been born in Illinois. Hall of Famers include Rickey Henderson, Kirby Puckett, Robin Yount, Lou Boudreau and others. Over 40 major league managers have been born in Illinois and include several Hall of Famers such as Whitey Herzog.
There have been two major league teams in Chicago since the creation of the American League in 1901, but the lack of other very large cities in the state has meant that the highest level of the game has been limited to the Windy City since the demise of the National Association. Minor league baseball has been widespread throughout the state, however, with the Three-I League and the Illinois State League revolving around the state. In the 21st century, the Midwest League includes a number of Illinois-based teams, as does the independent Frontier League. Illinois was also at the heart of the All-American Girls Professional Baseball League in the 1940s.