1. On December 1, 1818, Illinois was admitted as the 21st state of the United States. This came after a lengthy process in which the territory had to draft a constitution and gain approval from Congress.

2. In 1847, the Illinois and Michigan Canal was opened to navigation on December 1. The canal connected the Great Lakes to the Mississippi River and helped to spur economic growth in the state.

3. On December 1, 1955, Rosa Parks was arrested for refusing to give up her seat on a Montgomery, Alabama, bus. Her act of civil disobedience sparked a nationwide movement, including in Illinois, where activists fought for an end to segregation and discrimination.

4. In 1985, a memorial to the victims of the Haymarket Riot was dedicated in Chicago on December 1. The riot took place in 1886 and resulted in the deaths of several people, including police officers and protesters. The memorial honors those who died and also serves as a symbol of workers' rights and the labor movement.

5. On December 1, 2011, Illinois Governor Pat Quinn signed legislation that made Illinois the 16th state to allow same-sex couples to enter into civil unions. The law provided legal protections and benefits to same-sex couples that were previously only available to opposite-sex married couples.