It is a smaller celebration than normal this year, but for many people who have been cooped up inside for much of the last year and a half, it is a welcome taste of normalcy.
"They're having a blast. We didn't think this would be possible but the conditions are good and there's enough room to be socially distant and still have a good time," said father Jason Preston.
The kids' area at the fest is free Monday, giving them an opportunity to try their aim kicking a soccer ball at the target, or putting on an inflatable suit and running into people on the knockerball field.
Organizers were unsure what to expect but they said it's turned out well.
"This is like our kickoff party for the summer," said Jennifer Anderson with Hometown Fest.
In Mundelein, they are also celebrating July 4th on the 5th with a parade, which is something many communities canceled this year.
Arlington Heights is among areas that canceled their celebrations, where Frontier Days are a longstanding tradition. This would have been the 45th year.
Normally they have a parade and big national music acts, but the timing of the state moving into phase 5 from the pandemic this year made planning very difficult.
"It was just too late for us to plan everything, like book all the bands like we normally do," said Jim Glueckert, co-chair of Frontier Days.
However, they were able to book their carnival operator to set up rides and games.
Organizers said they are getting good feedback from residents who were anxious to get out and celebrate the Independence Day, but also the freedom to gather in groups of people again.
"It's good to see everybody come out on a day off of work," said Arlington Heights resident Johna Cary.