Published in 1873 by O.W. Gray & Son for their celebrated national atlas, this detailed map captures Michigan during an era of rapid industrial and infrastructural expansion. The map comprehensively delineates the state's growing rail network in the post-Civil War period, emphasizing the pivotal connections linking Detroit, Grand Rapids, Lansing, and various timber and mining ports along Lakes Michigan, Huron, and Superior. Every county across the Lower Peninsula and southern reaches of the Upper Peninsula is individually hand-colored with distinct pastel washes, overlaid with the Public Land Survey System township and range grid. An inset at the upper right titled 'Part of Northern Michigan' details the mineral-rich western Upper Peninsula, highlighting Ontonagon, Houghton, and Keweenaw counties during the height of the copper and iron mining boom. Nautical distances across Lake Michigan connecting ports in Wisconsin and Illinois are clearly marked alongside prominent shoreline features, islands, and straits.