1) On September 7, 1818, Illinois was admitted as the 21st state of the United States. This was significant as it marked the expansion of the country westward and the establishment of a new state.

2) In 1868, the Great Chicago Fire began on September 7, causing widespread destruction and devastation in the city. It burned for three days, destroying over 17,000 buildings and leaving over 100,000 people homeless.

3) On September 7, 1901, Illinois Governor Richard Yates signed a law creating the Illinois Industrial Home for the Blind, which was the first state-run facility for blind individuals in the country.

4) In 1940, the groundbreaking ceremony for the construction of the Illinois Tollway was held on September 7. The first section of the tollway opened in 1958, and it has since expanded to a network of over 290 miles.

5) On September 7, 1979, the University of Illinois Urbana-Champaign became the birthplace of the ARPANET, which is considered the precursor to the modern internet. Researchers at the university successfully transferred data over a network using the TCP/IP protocol, which would become the foundation for the internet as we know it today.