Racially restrictive housing covenants were once common in Baltimore. Eventually, federal rules and regulations locked in even sharper barriers to mortgage loans and housing access. A traveling exhibit titled, “Undesign the Redline,” now at the Central Branch of the Enoch Pratt Free Library, uses maps and stories to show how explicit racism became structural. Facilitator Trent Hall tells us about the exhibit. He hopes visitors leave with a sense of purpose.