United States Map 1873 Geological Print - New York, Chicago, San Francisco

This geological map of the United States was compiled by Charles H. Hitchcock, professor of geology at Dartmouth College, and published in 1873 by Stedman, Brown & Lyon of Philadelphia as part of Gray's Atlas of the United States, a first-edition atlas notable for reusing and updating older Colton state maps nearly two decades after their original issue. The sheet's defining feature is its color-coded classification of the country's geology, with distinct tints marking out Tertiary, Mesozoic, Cretaceous, and volcanic formations across the whole of the continental United States, a scientific rather than political organizing principle unusual among general atlases of the period. It covers the entire country from coast to coast, and it was produced just as postwar industrial expansion was driving new demand for precise knowledge of where coal, minerals, and building stone actually lay beneath American soil.

The Tertiary and Cretaceous formations sweep across the Gulf Coast and Great Plains, while older Mesozoic and volcanic rock dominates the mountainous West, giving the map a visual logic entirely separate from the state lines drawn over it. State boundaries, major rivers, and mountain ranges are still recorded to anchor the geology to familiar geography, and a legend in the corner translates the color key for a general audience rather than a specialist one. Hitchcock's academic credentials, prominently credited in the title block, lent the sheet a scientific authority that plain political maps of the period did not carry. Altogether it captures a country whose mineral wealth was only beginning to be systematically charted.

This map rewards anyone drawn to the history of American science or resource industries, whether a geologist, a mining history enthusiast, or simply a collector who wants something more unusual than another political state map on the wall. Its bold color scheme also reads well as a decorative piece, distinct from typical Victorian atlas maps. It is available unframed in a full range of sizes, from a compact study print to a larger statement piece.