The history of Dyeing the Chicago River Green

If you visit Chicago during St. Patrick’s Day, you will undoubtedly witness one of the strangest traditions in the country: the river dyeing. For five decades, Chicago has put on a shade of bright emerald green that matches that of the people celebrating, by dumping 40 pounds of environmentally friendly dye right into the Chicago River.
References are as below:

Dyeing the Chicago River green is a St. Patrick’s Day tradition. How did it start?
How Do They Dye the Chicago River Green for St. Patrick’s Day?
Is the Chicago River Dye Eco-Friendly? Behind the St. Paddy’s Day Tradition
Chicago River To Be Dyed Green Again, And Parades Are Back For St. Patrick’s Day Weekend
Why Do We Wear Green on St. Patrick’s Day?