United States Map 1874 Geological Print - New York, Chicago, San Francisco

This geological map of the United States was compiled in 1874 by Charles H. Hitchcock and William P. Blake for the U.S. Census Office and lithographed by Julius Bien in New York, published as part of the Statistical Atlas of the United States based on the results of the ninth census of 1870, a government atlas compiled under Francis A. Walker with contributions from leading scientists across several federal departments. What sets this sheet apart is its classification of the entire country into nine distinct geologic units, each rendered in its own color, a scale of scientific ambition unusual even for an official government publication of the period. It covers the whole of the continental United States, and it was issued at a moment when the federal government, having just completed its first postwar census, was treating geological knowledge as a matter of national economic planning rather than academic curiosity alone.

The nine geologic units sweep across the map from the ancient rock of the Appalachians to the younger formations of the Great Plains and Pacific coast, each explained in a legend set in the lower left corner. State boundaries are retained as a reference grid over the geology, letting a viewer read mineral and rock distribution against familiar political lines. The map's north-south orientation and broad 1:7,200,000 scale were chosen deliberately to give planners, prospectors, and railroad surveyors a continental overview rather than local detail. Compiled under direct congressional authority, the sheet reflects a federal government actively cataloging the country's underlying resources in the years following the ninth census.

A collector or researcher interested in the history of American science and federal statistics will find this map a natural fit, as will anyone who wants a wall map with genuine scholarly weight behind it. It stands apart from Gray's 1873 geological map of the same country by carrying the authority of an official U.S. Census Office publication rather than a commercial atlas house. It is available unframed in a full range of sizes, from a compact study print to a larger statement piece.