This year's theme, "A Parade of Countries: Rancho Cucamonga's Passport to the World," featured local schools and organizations that embraced the cultural theme.
"I'm so astounded at our entrants," said Gary Ablard, parade chairman. "They really embraced their heritage and were proud to show it. That's exactly what we wanted."
Founders Day is an annual tradition celebrating the city's incorporation in 1977.
Cheryl Ellis of Riverside and her family got seats close to the parade's starting point at Kew Avenue and Mainstreet.
They were there to support six girls in their family who were part of Remix All Stars, a dance and cheer academy.
"It was perfect," Ellis said.
This was Ellis' first time at the parade, which she thought was well organized and enjoyed the theme.
"It was great getting to see all the different levels of people," she said.
Ablard, along with Jennifer Camacho and Michelle Dazalla, and the rest of the team in charge of the parade, thought the theme would fit well in a diverse Rancho Cucamonga.
"We wanted to do something that everyone could participate in," Ablard said. "Everyone has their own heritage. We wanted everyone to highlight their culture."