It's Casimir Pulaski Day! IYKYK

There's no school and banks and government offices are closed in the state of Illinois in honor of Casimir Pulaski Day. Celebrated on the first Monday in March, Casimir Pulaski Day is in member of the Revolutionary War hero who is also considered the father of the U.S. Cavalry. Pulaski is also one of only eight people to be awarded honorary United States citizenship.

The reason Casimir Pulaski day is celebrated in Illinois is because the city of Chicago has the largest Polish population anywhere in the world outside of Warsaw. Thus, for many years Pulaski was celebrated with festivals and parades around the city of Chicago. And in 1977, the day became a state holiday.