The first Dairy Queen restaurant opened in Joliet, Illinois, US.
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The first private research atomic reactor opened in Chicago, Illinois, US.
The first Sears retail store opened in Chicago.
The world's most infamous clown, John Wayne Gacy, went on trial after he murdered 33 young men in Cook County, Illinois.
The first Mormon Pioneers left their homes in Nauvoo, Illinois, and began the long trek to the Salt Lake Valley.
The FDA approved the first oral contraceptive pill called Enovid.
