For their kids, it was just a fun day for a spin on the carrousel or the Big Dipper roller coaster.
The amusement park is closing because of a family rift between the part that owns the land and the members who operate the park.
"I started coming here after I had kids. They love it, and it's so close. They're sad. It's a sad day," said visitor Carla Racanelli.
"I'm going to miss it. It's the last day. I'm not going to see it any longer," said Lisette Valeriano, also a visitor.
Hundreds of visitors began lining up before the 12 p.m. opening of the amusement park , hoping to savor their past and present.
"It's sad that they won't grow up to take their kids here. My husband doesn't cry, but he was sad. It's very sad they couldn't work things out," visitor TJ Pleva said.
Like everyone else, former Kiddieland employee Kim Goldschmidt and his wife Susie tried to enjoy the park for the last time.
"I remember the grandfather who was the original owner and the two sons-in-law that worked here. They would give me the big rides. I'd work the ferris wheel," the former employee said.
As the park opened Sunday, 9-year-old Nicholas Martorina was the first kid in line for the bumper cars on Kiddieland's last day.
"It feels awesome because I've never been first in line for anything," he told ABC7 Chicago.
Founded in 1929 by Arthur Fritz, Kiddieland opened during the Great Depression as a sanctuary for families. Over the years, future generations managed it, but now a dispute between family members who manage the park and own the land means it will be no more.
"It's just got an emotional rollercoaster. You go from the joy to the tears. That's how it's been," said Tom Norini, Kiddieland co-owner.
It's the same for current park workers. Genevieve Rivera says she'll miss the kids the most.
"They come up to us this year and say, 'We're so sad it's closing.' It breaks my heart to see their faces so sad," Rivera said.
Although Sunday was the final day of the last U.S theme park that caters exclusively to children, it's a first for the Williams family, who hopes to keep Kiddieland alive in their own way.
"Hopefully, we'll have memories to treasure, hopefully," visitor Carl Williams said.
Family members who manage the part say they hope to sell of the equipment.
The park's gates were set to close Sunday at 8 p.m.