The city of Wausau, Wisconsin had an ordinance banning the throwing of projectiles, including snowballs, on city property since 1962. The law was finally amended at the end of 2019 to exclude snowball fights. – WTF Fun Facts
Source: https://www.theguardian.com/us-news/2019/dec/24/game-on-wisconsin-town-to-legalize-snowball-fights-after-50-year-ban