The indentures were extended and then made permanent, but technically, there is no slavery. The modern Civil Rights movement started before Brown. Adam Clayton Powell was integrating New York City lunch counters before then. Many of the students relied on employment and crime statistics from 1989. Those figures are usually available yearly for crime and monthly for unemployment.
Current statistics show that blacks and whites are earning equal amounts in many areas.
One of the students did not understand a quote by Spike Lee. This is always a problem with students. They got what they thought was right, but it really speaks to another issue. Lee's quote deals with the problem of shades of color used by blacks to discriminate against themselves. Some of your students are painting with a rather broad brush.