St. Patrick’s Day parades across the U.S. are going on Saturday, promising to turn a river green in the Midwest, commemorate a big anniversary in the South and put forth the first female leader of a major beer company as a grand marshal of the New York parade that predates the nation’s founding.

The holiday commemorates Ireland’s patron saint and was popularized largely by Irish Catholic immigrants. While St. Patrick’s Day falls on March 17, it’s being observed with major parades a day early, so it doesn’t land on Sunday, a day of worship for the Christian faithful.

Bagpipers march along Fifth Avenue during the St. Patrick's Day Parade, March 16, 2024, in New York.

Bagpipers march along Fifth Avenue during the St. Patrick’s Day Parade, March 16, 2024, in New York.

Manhattan’s St. Patrick’s Day Parade, which dates to 1762, is one of the world’s largest Irish heritage festivities. So many people march the 2.4-kilometer route up Manhattan’s Fifth Avenue that the parade is expected to last more than five hours.

On Saturday, Heineken CEO Maggie Timoney plans to serve as grand marshal of the Manhattan parade, according to organizers. Originally from Ireland, she is the first female CEO of a major beer company.

New York City has multiple parades on various dates around its five boroughs — including, on Sunday, the first St. Patrick’s Day parade allowing LGBTQ+ groups to march on Staten Island.

Mayor Eric Adams last month announced the plan for the new, privately organized celebration, arranged after a local organization asked for years to join the borough’s decades-old parade. That longstanding event, which does not allow groups to march under LGBTQ+ banners, happened earlier this month.

The Manhattan parade began allowing LGBTQ+ groups and symbols in 2015, after decades of protests, legal challenges and boycotts by some politicians.

Members of the Chicago Journeymen Plumbers Local 130 dye the Chicago River green ahead of St. Patrick's Day celebrations, March 16, 2024, in Chicago.

Members of the Chicago Journeymen Plumbers Local 130 dye the Chicago River green ahead of St. Patrick’s Day celebrations, March 16, 2024, in Chicago.

The Chicago Plumbers Union once again turned the Chicago River green. Organizers say the tradition, started by the union, uses an environmentally friendly powder once used to check pipes for leaks.

In Savannah, Georgia, organizers expect a historic crowd to participate in the parade, which started in 1824. Ahead of the bicentennial, Georgia’s oldest city had nearly 18,000 hotel rooms booked for the weekend.