Polish Constitution Day Parade

The Polish Constitution Day Parade in Chicago is widely recognized as the largest Polish parade outside of Poland. It commemorates the anniversary of the ratification of the Polish Constitution of May 3, 1791, which established a constitutional monarchy with three separate branches of government—legislative, executive, and judicial—and extended political rights to the nobility, bolstering the role of the bourgeoisie, and granting protections to towns and peasantry.

Source: Wikipedia — Polish Constitution Day Parade (CC BY-SA 4.0)