Residential Security Map, 1937This map from 1937 was developed by the Home Owners’ Loan Corporation (HOLC ) The purpose of this, and all of the maps produced by HOLC, was to provide guidance to lending institutions refinancing mortgages in default in order to prevent foreclosures during the depression. On the Kalamazoo residential security map, the newest areas — those considered most desirable for lending purposes — were colored in green and labeled "A". "B" neighborhoods were considered desirable and colored blue. Older, "C" neighborhoods were viewed as declining and are colored yellow. "D" neighborhoods are colored in red and were considered the most risky for mortgage lenders. The term "red lining" comes from these maps. This map is made available by the University of Richmond Mapping Inequality Project.