The first Dairy Queen restaurant opened in Joliet, Illinois, US.
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The first Sears retail store opened in Chicago.
Illinois became the 21st state to join the United States of America.
The FDA approved the first oral contraceptive pill called Enovid.
An F5 max rating tornado smashed through Plainfield, Illinois, killing 29 people, injuring 353, and causing $165 million in damages.
The world's first self-sustaining nuclear chain reaction happened in Chicago Pile-1 at the University of Chicago. It was overseen by Enrico Fermi.
