Noting that the attack has drawn worldwide attention, organizers hope the rally will spur discussion about sexual violence committed against children in urban communities.
Trenton Mayor Doug Palmer and hip-hop mogul Russell Simmons were among those in the standing-room only crowd gathered at a church just a few blocks away from the Rowan Towers apartment building, where authorities say the girl was assaulted March 28.
Police say the girl's 15-year-old stepsister took her to a party there with some men, then sold sex to men in the room. She then took money to let them touch the younger girl and the touching turned to forcible sex.
Two men and three teenage boys have been charged so far in the attack.