It was a program he started 12 years ago.
"At that time they had barriers, you couldn’t come in. Now we broke all those barriers down," Daley said, speaking at Orr Academy High School. "How do you connect people into a public school system? Most people view public school systems, 'Hey I pay my taxes. You’re supposed to perform. You go do it.'"
The program has been a big success for the mayor, who very publicly took personal responsibility for the school system.
"After 21 years, the greatest opportunity I had was to take responsibility for public schools," he said.
Daley thanked big donors, such as the CEO of Sachs Capital group, for contributing $100,000 for a new stock market program at John F. Kennedy and TEAM Englewood High Schools.
He said everyone should contribute and be a role model.
"Parents have to sacrifice. They have to have their own drives, whether it's washing cars or volunteering, $500 or $100, because they bought into the system."
When Principal for a Day started in 1998, there were 677 participants. There were more than 1,500 on Thursday, with the program raising hundreds of thousands of dollars.
Those donations stirred some controversy earlier in the week week when it came to light that the registration form for volunteers seemingly required a donation of $1,000.
Chicago Public Schools CEO Ron Huberman later clarified, saying it was meant to be a just suggestion to donate, not a requirement.
After the final bell rang, the Principals for a Day and their school hosts attended a reception at the Navy Pier Grand Ballroom to honor the mayor for his vision.