Hundreds took part in a historic swim in the Chicago River on Sunday, according to multiple reports.

The Guardian reported that the organized swim was the first of its kind in close to 100 years. The number of participants in the event came close to 300, according to The Chicago Sun-Times.

“Reclaiming our river not only creates a recreational space for residents and visitors, but it also puts us on the map, along with other global destinations, where open-water swims have become part of city culture,” Chicago Mayor Brandon Johnson said when the swim started, according to the Sun-Times.

A webpage for the event states that it “will close the loop on the full, and once-unthinkable, rebirth of the Chicago River.”

“This civic renaissance brings Chicago into a unique peer group of cities that have reclaimed their urban waterways, including Amsterdam, London, Paris and New York City,” the webpage continues.

“Tremendous public and private support stand behind the Chicago River Swim concept, including pent-up demand from hundreds of experienced swimmers and countless local businesses and community advocates.”

In May, Health and Human Services Secretary Robert F. Kennedy Jr. unveiled that he took a dip in Rock Creek in Washington, D.C., alongside his grandchildren in spite of long-standing warnings about high bacterial levels. 

Late last year, a Chicago court ruled that the city’s Trump Tower broke state environmental protection law with its use of water from the Chicago river.In a ruling, Cook County Circuit Court Judge Thaddeus L. Wilson backed a 2018 lawsuit by Illinois Attorney General Kwame Raoul (D) and a coalition of environmental groups.