Group marched from Millennium Park to Pioneer Court in a show of solidarity for slain Florida teen Trayvon Martin.
A crowd of about 200 people that had gathered at Chicago's Millennium Park swelled with hundreds more before marching down Michigan Avenue in a rally cry for justice for Trayvon Martin.
"It's a horrendous thing," said Anne O'Brien of the shooting death of the Florida teen by a neighborhood watchman. "I think that this, if nothing else, it gets people thinking when they see a bunch of people demonstrating."
The shooting may have happened states away, but it has captured the attention of the nation and has drawn parallels to the killing of Emmett Till by a group of white men in the south in 1955.
"We're really saddened that after 57, 58 years from Emmett's death this is still going on, that there are such injustices that are still occurring," said Till's cousin, Airickca Gordon-Taylor, who was among Friday's protesters.
Even President Barack Obama weighed in on the topic from Washington, D.C., saying if he had a son it would probably look like Martin.
Earlier this week, students at Chicago State University joined in a Million Hoodie March, one of several across the country, in protest of Martin's death.
The "Occupy Chicago" group has also planned a "We are Trayvon Martin" protest from noon to 3 p.m. on Saturday at Daley Plaza.
Martin was shot after going to a nearby store for Skittles and tea, his parents and police said. The watchman who admits to shooting Martin, George Zimmerman, has not been charged.