CHICAGO (CBS) —  It was bumper-to-bumper traffic as people throughout the area celebrated Mexican Independence Day.

Some waved Mexican flags from their cars while others honked their horns as they rode down the expressway.

According to the Pew Research Center, more than a million and a half people of Mexican descent live in the Chicago area.

While often confused with another popular holiday, Cinco de Mayo, Mexican Independence Day was established in 1810 and is celebrated on September 16.

It was a priest, Miguel Hidalgo, who led Mexicans to demand independence from Spain.