The “Delmar Divide” refers to Delmar Boulevard in St. Louis. It is a street which runs east/west and to a large extent separates the racial make-up of the city. In a sample of households north and south of Delmar, residents south of Delmar Boulevard are 73% white, while residents north of Delmar are 98% African American, as the BBC pointed out in, “Crossing a St. Louis street that divides communities,” last year.
Jack Straughter was a pipefitter in the 1960s when he and his wife were looking for a new house for their family of seven, and so he could have afforded to live almost anywhere in the city of St. Louis. But as a black man, there were places he never considered looking.