Same-sex marriage was legalized across the United States on Friday, but the celebrations continued long into the weekend. Sunday marked Gay Pride Day and many stars took to Instagram to show their support. Lady Gaga was in Chicago, where she watched the Windy City's parade from a balcony. "Watching over Chicago Pride from my apartment and smiling so big. So many happy people. Happy pride!! #lovewins," she captioned a photo (above) that she shared on her Instagram, which shows her happily throwing her hands in the air, the words "gay" and "pride" written across her chest and stomach. And she wasn't the only one having fun—keep reading to see all of the best celebrity Instagrams from the weekend.