Detailed map of Chicago, published by O.W. Gray & Son.
The map is colored by wards and showing streets, rail lines, parks, buildings, stations and a host of other details.
One of the earliest maps of Chicago to appear in a commercial atlas.
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.