Penny Petersen is one of the co-founders of the Mapping Prejudice Project and is a leading expert on historic property records in Minnesota. After retiring as a researcher for a Minneapolis-based historical consultant in 2015, Petersen spent countless hours in the Hennepin County Recorder’s Office identifying thousands of deeds encumbered by racial restrictions. This work only intensified after Mapping Prejudice launched its Zooniverse platform for crowd-sourcing deed transcription with more than fifteen thousand property records completed online