The students-turned-activists have become powerful national voices with their "March For Our Lives" campaign pushing for reform of gun laws, following the February 14 mass shooting at Marjory Stone man Douglas High School which killed 17 students and school staff.
The students were from more than 20 states, with the goal of registering young people to vote and advocating for tougher gun control measures.
The students chose Chicago for their first stop because of its runaway gun violence. There were 950 shootings in the Midwestern city so far this year and more than 220 murders.
The students said they wanted to highlight not just headline-grabbing mass shootings but daily violence that contributes to 33,000 gun deaths in the US annually.
They also pressured Florida state lawmakers to tighten gun laws by, among other things, raising the legal age to buy a firearm from 18 to 21.
The annual end-of-school-year rally to highlight gun violence in Chicago was a friendly stop for the students.
They will head on Saturday to the conservative Chicago suburb of Naperville, where gun control is a less welcomed topic. Future stops are planned in Kansas, Iowa and Wisconsin, among other states.
