An intricate late nineteenth-century county map of the state of Michigan published by the prominent American cartographic firm G.W. & C.B. Colton & Co. The map depicts the Lower Peninsula in great detail alongside the eastern portion of the Upper Peninsula, the Straits of Mackinac, and adjacent waters of Lake Michigan, Lake Huron, and Lake Superior. Individual counties are distinguished by delicate original hand coloring in pastel shades of pink, yellow, green, and blue, overlaid with township survey grids, county seats, post offices, and settlements. The map provides vital historical documentation of Michigan's rapidly expanding transportation infrastructure following the American Civil War. Completed and projected rail lines crisscross the southern interior, extending northward into the lumber and mining corridors. Marginal notation includes an 'Explanations' key detailing cartographic symbols, double-longitude scales referenced from both Washington, D.C., and Greenwich, and distance checks along rail routes indicating miles between stations.