The Pennsylvania and New York Geological Surveys received authorization in 1836, within days of each other. Their authorization ended in 1842, within a few months of the other. Largely through the indomitable characters of James Hall and Henry Rogers, after authorization lapsed, both Surveys continued and produced large, important volumes on the geology of their respective states that set the framework for much of the later geological survey work of the Appalachians.
New York had its John Dix, who was the Secretary of State, and Pennsylvania had its Charles Trego, Member of the House of Representatives - both government officials who shaped the course of each Survey. But the differences in the Paleozoic rocks - thin, ubiquitously horizontal and replete with fossils in New York; thick, repetitively folded and faulted, with fewer well-preserved fossils, in Pennsylvania - determined the approaches and results of these Surveys.
From the efforts of the State Geologists of New York and Pennsylvania, along with Edward Hitchcock of Massachusetts, was born the Association of American Geologists, this later to became the American Association for the Advancement of Science. Not all of the interactions between the two surveys were to be so cooperative. Hall sought to obtain other states' information for his maps. Refused by Henry Rogers, Hall circumvented him by contacting Charles Trego, who later became an impediment to Rogers' plans for publication of the Pennsylvania reports.