The Peace Warriors, a group of predominantly black high school students from Chicago, have been fighting gun violence for 10 years without garnering much attention from the outside world. The students from Parkland, Fla. brought the issue to national prominence in a matter of days. So when the Chicago youth group from North Lawndale College Prep High School met the Marjory Stoneman Douglas High School teens in Florida last month to discuss their common cause, many in the room had the same unspoken thought.