Cameron, who had taken two CPR courses in the last year, put his training to work and eventually helped revive the 5-year-old.
"I'm glad I paid attention in class," Cameron told the newspaper,
It was first-hand experience of the importance of the life-saving technique.
"If everybody, or at least one person in a business or household, knew CPR, I think a lot more lives would be saved every day," he said.
Receiving CPR minutes after cardiac arrest can double the chance of survival for a person, according to the American Heart Association.
Jerry Johnson, the fire and life safety educator with the Mokena Fire Protection District, where Harper was trained, said he's heard estimates than an additional 100,000 to 150,000 lives per year could be saved if everyone above age 10 knew CPR.
"I think everyone should be trained," he said.
People who don't use CPR in their day-to-day job should aim to take the training once a year, Johnson said. Classes are available through many local fire districts and hospitals.