W.E.B. Du Bois conducted his pioneering sociological study, The Philadelphia Negro (1899), in the Seventh Ward, which was bounded by Spruce Street on the north, South Street on the south, Sixth Street on the east, and Twenty-Third Street on the west. At that time, the Seventh Ward contained the largest population of Blacks in the city of Philadelphia. This map was published as part of the study.
Map of the Seventh Ward of Philadelphia - 1899
From: Du Bois, W.E.B. Series in political economy and public law. The Philadelphia Negro; a social study by W.E. Burghardt Du Bois. Together with a special report on domestic service by Isabel Eaton. Vol. 14. Philadelphia: University of Pennsylvania, 1899.