An activist speaks out about her feelings about the unrest in Ferguson, Mo. during a vigil at Daley Plaza in Chicago Thursday, Aug. 14. Video by Megan Crepeau.

Hundreds of people crowded Daley Plaza on Thursday night for a rally against police brutality as repercussions of violence in Ferguson, Mo., hit Chicago following the shooting death of Michael Brown.

"I'm so mad right now I can't even speak. This hurts so bad," said Rachel Jackson, 23, breaking into tears as she addressed the crowd. "I'm so mad, but we are here, and you all came out, and I thank you for coming out, because this matters. We fucking matter."

Protesters held their hands up in a gesture of submission and stood silent for four minutes in memory of the four hours Brown's body reportedly was left on the street after the 18-year-old was shot dead by police in Ferguson on Saturday. Police say Brown was unarmed, but was shot during a scuffle with a police officer.

The Chicago rally was one of dozens planned across the country in what social media activists termed #NMOS14, for National Moment of Silence.

A handful of Chicago police on the scene hung back from the crowd, which remained peaceful. Officers on the scene declined to give an estimate of how many were in attendance; one organizer estimated the tally at about 700.

"We're standing here with our hands up. Our hands been up … and we're still dying. What are we supposed to do?" said organizer Malcolm London, 21, after chanting "black lives matter" so loudly his microphone started to malfunction.

As one attendee sang to the crowd, London crumpled to the ground, pressed his fists against his eyes and started sobbing.

Ferguson has been in disarray since Brown was killed. Protests have occasionally turned violent, with incidences of looting and vandalism. Demonstrators, politicians and activists have accused Ferguson police of using extreme tactics—such as tear gas, military gear and rubber bullets—that are out of proportion with the actions of the crowds.

The events in Ferguson have sparked outrage across the country—not least in Chicago, about 300 miles northeast, which has its own fraught history of police brutality, protest and officer-involved shootings.

"The people here feel as if the police don't care about protecting and serving them," said Kimberly Sewell, 26, one of the vigil's organizers. "It brews a little bit of anger inside of them. Why is so much police violence happening? Why aren't you doing what you're trained to do?"

Sewell, a special education teaching assistant, grew up in the Cabrini-Green housing projects, where she said there was a heavy police presence.

"I didn't seem to pick up a good vibe from them. They seemed a bit hostile, I guess, a little condescending," she said. "I felt that they didn't really care about the issues or protecting the people."

A statement from Chicago Police Department spokesman Martin Maloney said police would be respectful of the ralliers' First Amendment rights.

"The Chicago Police Department always works to ensure every group can exercise their right to assemble and their right [to] free speech, and that will be no different with tonight's rally," he emailed in a statement before the gathering.

Chicago's history of tension between citizens and police goes back a hundred years or more, according to Mariame Kaba, founding director of community justice group Project NIA.

"The [Chicago] police have had a hostile relationship to black communities for generations," she said. "The Jon Burge torture cases are not legend in most black communities; they're present-day realities."

Burge is a former Chicago police commander accused of torturing suspects to gain false confessions. Kaba also mentioned the violent 1968 Democratic National Convention, which was termed a "police riot" in an official report, and racist police action during the "Red Summer" riots of 1919.

"Ferguson is sparking the reaction it is nationwide because of the fact that so many people, especially black people, in this country have an antagonistic relationship with police," Kaba said.

According to Tribune data, there have been 34 officer-involved shootings in Chicago so far this year. Of those, 32 suspects were injured or killed by police, and two officers were injured.

Pat Camden, a spokesman for the Fraternal Order of Police, said officers were not anticipating a Chicago repeat of Ferguson violence at Thursday's rally or after.

"From the union perspective, that's not something that we're hearing, and that's not the case," he said. "Hopefully [the protesters] will peacefully express their First Amendment rights."

Before Thursday's rally, Sewell said she could see Ferguson-style violence happening here—but she said she hoped the rally would be a positive outlet for frustrated feelings "before it reaches that exploding point."

"We're getting fed up with what was going on," she said. "Possibly one day those will all come to a head … tonight's vigil is to just allow us a moment to grieve and to mourn and to let out all those feelings of sadness and things like that so we can start having a clearer head on how to attack these issues."