Scarce large map of the United States, published in Boston by Walling & Gray.
The map is hand colored by state and showing towns, railroad routes, explorer's routes etc. Shows a number of early railroad routes in the West.
the map shows the now completed route of the Union Pacific / Central Pacific Railroad, along with the proposed routes of tne Northern Pacific Railroad and the Southern Pacific Railroad.
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.