1. On May 27, 1832, the Black Hawk War broke out in Illinois. The conflict was between the United States and several Native American tribes, led by Chief Black Hawk of the Sauk tribe. The war lasted for several months and resulted in the removal of Native Americans from Illinois.

2. May 27, 1871, marked the opening of the first public zoo in the United States, the Lincoln Park Zoo in Chicago, Illinois. The zoo is still in operation today, and has expanded significantly over the years.

3. In 1933, the first drive-in movie theater in Illinois was opened on May 27 in Galva. The theater, called the Park-In, could accommodate up to 400 cars and was a popular destination for families and couples throughout the 20th century.

4. Illinois native and Baseball Hall of Famer Lou Boudreau was born on May 27, 1917. Boudreau played for the Chicago Cubs and Cleveland Indians during his career and was known for his outstanding defense and clutch hitting.

5. On May 27, 1963, the University of Illinois at Chicago Circle (now known as the University of Illinois at Chicago) was established. The university has since grown to become one of the largest public research universities in the country, with a diverse student body and a wide range of academic programs.