On March 3, 1879, by an act of Congress, the United States Geological Survey (USGS) was established. It was charged with the "classification of the public lands, and examination of the geological structure, mineral resources, and products of the national domain." From USGS Circular 1050: "The legislation stemmed from a report of the National Academy of Sciences, which in June 1878, had been asked by Congress to provide a plan for surveying the Territories of the United States that would secure the best possible results at the least possible cost."

The Survey was established, in part, in response to the westward expansion of the territory of the United States. From the History Channel: "Although the rough geographical outlines of much of the American West were known by 1879, the government still had astonishingly little detailed knowledge of the land. Earlier federal exploratory missions under men like Ferdinand Hayden and John Wesley Powell had begun to fill in the map, yet much remained to be done. Congress decided to transform the earlier system of sporadic federal geological explorations into a permanent government agency, the United States Geological Survey."

Happy 129th birthday, USGS!