St. Patrick’s Day originated as a celebration of the death of Saint Patrick, the patron saint who was responsible for bringing Christianity to Ireland. In the early seventeenth century, it was made an official feast day and gradually become a celebration of Irish culture all over the world.

In Chicago, it is tradition to dye the Chicago River green. This tradition began in 1962. They use about 40 pounds of green vegetable dye to keep the river green for several hours.