According to Choose Chicago, the city's tourism promotion body, there is nothing quite like St. Patrick’s Day in Chicago, "when Irish taverns fill with revelers, cultural celebrations pop up in every corner of the city, and the Chicago River sparkles brilliant shades of emerald green."

The history of St. Patrick’s Day in Chicago goes back more than 175 years. Now a longstanding tradition, Chicago’s Irish parade was first held in 1843 and became an official city event in the 1950s. The dyeing of the Chicago River was added in 1962, quickly becoming one of Chicago’s most famous events, it said.

Along with the downtown festivities, Chicago’s proud Irish heritage is also on full display in its neighborhoods — from Beverly (a traditionally Irish enclave) to the Irish American Heritage Center near Albany Park.

The streets were teeming with celebratory crowds wearing the green gears of St. Patrick's Day- from hats to T-shirts and green sequin outfits.

According to Choose Chicago, the Chicago River dyeing is one of the most unique St. Patrick’s Day celebrations in the world. Typically held the Saturday before St. Patrick’s Day (the same day as the downtown parade), this bucket-list event is a beloved tradition that dates back over half a century.

The best place to watch the St. Patrick’s Day spectacle, now in its 69th year, is along the Chicago River between State and Columbus. The lower Riverwalk is closed, but spectators can watch from Upper Wacker and the many bridges.

The green river dyeing starts at 10 a.m.

The first time the Chicago River was dyed green was in 1962, thanks to a suggestion from the local plumbers union. That first river dyeing turned the waters green for nearly a month — nowadays, the color only lasts for a few hours.

The plumbers union still holds the river-dyeing honors today, and their environmentally friendly dye formula remains a closely kept secret.