Large map of Philadelphia, with a smaller regional map and yet a third map showing the 23rd Ward. From one of the leading American map publisher of the 1870s and 1880s.
Nice large format map.
O. W. Gray was a publishing firm based in Philadelphia. Later, they published as O. W. Gray & Son. They published atlases in the late nineteenth century. Gray's National Atlas was one of the most successful commercial ventures of the 1870s and one of the last to employ hand coloring on maps.