Printed map of the heart of Los Angeles with lines sketched in to show geographic distribution of African Americans, created sometime between 1923 and 1930. The map indicates dense African American populations along Jefferson Blvd, from Arlington to Vermont, and north of Slauson between Central Ave. and the Los Angeles River. This map was used to define what areas of the city to keep for white people to live in, and to block black migration. The practice was a way to prevent integration with African Americans based on the belief that when blacks move into white working class neighborhoods, the property values go down triggering urban blight. This exclusionary practice was known as “red lining”.