1. In 1971, the Illinois tollway system officially opened to motorists. The system includes more than 292 miles of roadway in Northern Illinois and has been deemed one of the most efficient and innovative tolling systems in the world.

2. On October 2, 1951, the University of Illinois became the first university in the country to use a nuclear reactor for peaceful purposes. The reactor was used for research, including the production of isotopes for medical purposes.

3. In 1871, a devastating fire swept through the city of Chicago, destroying much of the city and leaving an estimated 100,000 people homeless. The fire began on October 8, but its origins are believed to date back to October 2, when a fire broke out in a barn on the city's South Side.

4. On October 2, 1915, a young lawyer named Clarence Darrow successfully defended Eugene V. Debs, a labor leader and socialist, against charges of sedition. Debs had been arrested for making a speech criticizing the government's handling of World War I.

5. Illinois became the 21st state in the United States on December 3, 1818, but the territory that would become Illinois was first explored by French explorers in the 17th century. In 1673, French explorer Louis Jolliet and Jesuit missionary Jacques Marquette navigated down the Illinois River to the Mississippi River, exploring the region and interacting with local Indian tribes.