Every year, Chicago transforms its iconic river into a bright, vivid green to celebrate St. Patrick's Day. This unique tradition has become one of the most recognizable aspects of the city’s festivities, attracting thousands of visitors and residents alike. But how did this unusual custom begin, and why does it happen every year?

The Origins of the Green River Tradition

The tradition of dyeing the Chicago River green dates back to 1962. The idea was the brainchild of Stephen M. Bailey, a member of the Chicago Plumbers Union. Bailey, along with other union members, wanted to create a fun and lasting visual spectacle for the city's St. Patrick's Day celebrations, showcasing Chicago's Irish-American heritage.

Originally, the union used an environmentally-friendly dye to help locate illegal sewage discharges in the river. Bailey saw an opportunity to repurpose the dye for the festive occasion. The first trial run of dyeing the river took place in 1962 when the river was turned a vibrant green for the St. Patrick’s Day parade. The response from the public was overwhelmingly positive, and it quickly became a beloved annual tradition.

How the River Is Dyed

Each year, the Chicago Plumbers Union and other volunteers work together to ensure the river remains green for several hours. The dye used is a special, eco-friendly fluorescent powder that is both safe for the river’s ecosystem and vibrant enough to create the stunning green color. Typically, around 40 pounds of dye are used, and the process takes about 45 minutes to complete.

The dye initially appears as a yellowish-orange hue before it mixes with the water, gradually turning the river into a striking emerald green. The dye is designed to dissolve and disappear within a few days, leaving no lasting impact on the river. shutdown123