After a brief career in the Congregational church, J. Peter Lesley (1819-1903) left the ministry in 1852 to work full-time as a geologist. Having gained experience in structural geology and stratigraphy with the First Pennsylvania Geological Survey (1836-1842), Lesley became an expert in the geology of coal, working for the Pennsylvania Railroad and other corporations and conducting some of the first systematic studies of the state's hydrocarbon resources. A long-time professor at the University of Pennsylvania, he was elected to the APS in 1856, serving variously as its librarian, secretary, and vice president, and he was selected as Director of the Second Pennsylvania Geological Survey (1875-1889). The Lesley Papers include letters to and from Peter Lesley and his wife, Susan on geology, coal and iron mining, abolition, educational reform, organized charity, and Unitarianism. The collection offers important insight into academic and applied geology in late 19th century Pennsylvania, the development of the coal and iron industries, as well as into the Lesleys' progressive social and intellectual milieu. It is divided into three series: Lesley's general correspondence, his correspondence with his brother Joseph, and microfilms of Lesley's research notes.

The most stellar member of a stellar family, Elisha Kent Kane was among the most popular American explorers of the mid-nineteenth century, a hero in the tragic mode. Born in Philadelphia in 1820, the son of John Kintzing Kane and Jane Duval Leiper, Kane studied medicine at the University of Pennsylvania before earning a commission as a naval surgeon. While in the Navy, Kane embarked on the succession of voyages to exotic locales that became the basis for his extraordinary fame. In 1843, he attended Caleb Cushing's first diplomatic mission to China as ship's physician, and subsequently traveled to the Philippines and Western Africa. Distinguishing himself in the Mexican War, Kane's greatest fame came from two expeditions to the arctic, aiming to locate the lost explorer, Sir John Franklin and to explore for evidence of the open polar sea. Kane died in 1857 while attempting to organize a third arctic voyage. Part of the Kane Family Collection, the Papers of Elisha Kent Kane contain a mix of personal and family correspondence with correspondence relating to all of Kane's explorations. Intelligent, articulate and very much a romantic, Kane's letters are expressive and passionate. The collection provides fine documentation of youth, his relationship with the Spiritualist Margaret Fox, and of course his travels to China and off the coast of Africa in 1846. Kane's two expeditions to the arctic are particularly well documented, with correspondence, notes, logbooks, diaries, and sketches, as well as Kane's post-expedition notes, writings, and lectures recounting his experiences.

In addition to family and business correspondence, the Charles Nicoll Bancker Family Papers contains various documents, such as a furniture inventory volume (30pp.); a Daybook, 1795-1800 (120pp.); and a very interesting journal (unidentified, but by one of the Banckers, and filed under "Description of a trip..."), from New York to Albany and back, between July 20-Aug. 15, 1793 (1 vol., 31 pp.). It contains detailed observations of the Hudson River and the towns along the way. Bancker was involved in business and trade prior to 1826, and in insurance after that date, so there is material relating to those topics in this collection. He owned a substantial library of the period, which was used by Charles Wilkes's Expedition after 1837 (see Reynell Coates to Bancker). This library, along with Bancker's notable scientific instrument collection, was sold after his death and there are published auction catalogues in the collection. There is much family correspondence from: Anne E. Bancker, Charles Gerard Bancker, Evert Bancker, Sarah U. Bancker, Violetta Bancker Talbot, Elizabeth Bancker Teackle, and John Teackle.