A crowd-size expert from the U.K. estimates that between 10,000 to 15,000 people attended Saturday's protest in downtown Chicago. But some estimates say 75,000 people gathered downtown.

Photos from the “No Kings” protest in Chicago on Saturday as part of an anti-Donald Trump rally on the same day as his military parade in Washington, D.C., for his birthday.

The Chicago Teachers Union will be joining the "No Kings" march in downtown Chicago on Saturday, June 14, according to the union's website. The march is scheduled for the same day a massive military parade is set to take to the streets of Washington in an elaborate showcase of troops, tanks, weapons and aircraft.

Organizers are calling for Americans to attend demonstrations across the country to protest President Trump on his 79th birthday.