These letters are principally to his brother John Cleaves Short, on personal, family, and general topics.

This collection contains mostly entomological material, with much information on the description and identification of particular insects, entomological collections, and the study of entomology in Europe and the United States. In addition, there are materials on medicine and hospitals during the American Civil War, on the Corps of Topographical Engineers, the United States Army, on natural history in the United States, and on the LeConte's family. Some letters are written to President Rutherford B. Hayes and concern the Commissionership of Agriculture, for which LeConte was considered, but not appointed. Letters of John Eatton LeConte and Joseph LeConte are included.

The collection of about 850 items covers the period from 1782 to c. 1936, with the bulk dating to the 1780s to 1840s. The collection is divided into four series. Series I contains correspondence relating to a wide variety of topics, including French and English politics, business, trade, religious matters, and personal affairs. Many of the items are letters of introduction. There is also information on John Vaughan's immigration to America, Joseph Priestley, vaccines and inoculation (with Jefferson's comments on the same), Vaughan's business in Philadelphia, and the American Philosophical Society. Also included in this series are 2 boxes with copies of Vaughan correspondence as well as miscellaneous notes by E. W. Madeira, gathered in the course of his research on Vaughan in the 1930s. Series II consists of three volumes. Included are two of Vaughan's commonplace books. One, entitled, "J. Vaughan's book," May 17, 1779 (47 pp., in Latin; 870/L34), includes mostly Latin notations. The other commonplace book, dated 1783 (ca. 66 pp.; B V 462.c), includes comments on several prominent Americans, such as Benjamin Rush and David Rittenhouse, as well as American society generally. The third volume is a copybook with thirty letters spanning the period 1784 to 1801 (B V462.1). Series III includes material relating to Vaughan's administration of the estate of the Philadelphia merchant Samuel Merrick, 1796-1822 (Vaughan-Merrick Papers, B V462.m; 2 boxes). Series IV consists of correspondence between Vaughan and the DuPont Co. for which he served as agent (B V462.4; photocopies of 73 letters).

Letters (including some transcripts and photostats) from and to Vaughan from many American and British correspondents, including: Also personal correspondence and business papers of Benjamin, Charles, Petty, Samuel Sr., Samuel Jr., William, William Oliver, and Sarah Vaughan (2 boxes); lectures, mostly in shorthand (3 vols.); a large number of notes and memoranda on a wide variety of topics, such as agriculture, architecture, astronomy, diplomacy, diseases, dueling, electricity, hieroglyphs, internal improvements, medicine, meteorology, land, manufactures, politics, punctuation, religion, silk-manufacturing, stock-breeding, taxation, Unitarianism, Benjamin Franklin, John Locke, Napoleon I, Joseph Priestley, Bowdoin College, town of Hallowell, Maine; notes on the peace negotiations, 1782-1783; miscellaneous legal papers; genealogy of the Abbott-Vaughan families. For a personal account of the collection, see Mrs. Mary Vaughan Marvin, "The Benjamin Vaughan Papers," APS Proceedings 95 (1951): 246-249.

John James Audubon (1785-1851), the American Woodsman, is a legendary naturalist and bird artist. His technique of painting North American birds dramatically as they appeared in their natural habitat was a major contribution to the emerging discipline of ornithology in the nineteenth century. His masterpiece, The Birds of America (1827-1838), elephant folio, was followed by a companion text edition, Ornithological Biography (1831-1849), a smaller octavo edition of Birds (1840-1844) and The Viviparous Quadrupeds of North America, published posthumously. This collection of original letters of publication information, ornithology, and some personal notes was sent primarily to Lucy Bakewell Audubon, his wife, from 1826-1834, and to Victor Gifford Audubon, his son, from 1833-1834, 1840-1844, with some sporadic contact with both between 1836-1839. Items in the collection relate to Audubon's Florida, Great Egg Harbor, and Great Pine Forest expeditions but not to his final expedition up the Missouri River. Of particular note, letters of 1833 and 1834 contain references to his response to the Academy of Natural Sciences of Philadelphia president George Ord's attacks on his credibility. A partial journal entry from New Orleans in 1821 and a few letters to other correspondents, including John Bachman, round out the material.

One of the oldest houses in Philadelphia, Wyck is now a non-profit museum listed on the National Register of Historic Places. Nine generations of the Jansen-Wistar-Haines family owned the Wyck property from 1690 until 1973. The last family owner deeded 2.5 acres of land, the house and its contents, several outbuildings, a landscaped garden, and a small endowment to the Wyck Charitable Trust. The Wyck Charitable Trust and the Wyck Association now administer the preservation of the property and its educational services to the public. This collection contains diaries, letters, accounts, bills and receipts, deeds, and photographs. The collection as a whole is deepest for the period 1770-1970. Items of particular note include accounts of household expenses at Wyck from ca. 1790-1970; papers pertaining to the Academy of Natural Sciences of Philadelphia, Quaker schools, and social reform groups; agricultural and horticultural practices; and correspondence to and from cultural leaders of 18th and 19th century Philadelphia. The papers of the John S. Haines family (Ms. Coll. 52A) form part of the Wyck Papers. The papers cover the years 1845 to 1949 and are arranged into eight series.

A physician, natural historian, and professor at the University of Pennsylvania, Benjamin Smith Barton (1766-1815) was one of the central figures in Philadelphia's early national scientific establishment. Having received his medical training in European universities, Barton was appointed Professor at the University of Pennsylvania in 1789, lecturing on botany, materia medica, natural history. A prolific author, he established his reputation as one of the nation's preeminent botanists through his botanical text book The Elements of Botany (1803), but his contribtions to zoology, ethnology, and medicine were equally noteworthy. Barton's monograph on the "fascinating faculty" of the rattlesnake and his efforts in historical linguistics (New Views of the Origin of the Tribes and Nations of America, 1798) were widely read, and his Philadelphia Medical and Physical Journal (1804-1809) was one of the nation's first medical journals and an important outlet for natural historical research. The Barton Papers offer a comprehensive view of the professional work of Benjamin Smith Barton from the time of his return to the United States in 1789 until his death. The collection is divided into five series: Correspondence, Subject Files, Bound Volumes, Graphic Materials, and Printing Plates. The collection includes a particularly valuable series of botanical, medical, and natural historical drawings collected by Barton for research, reference, and publication. Among the many artists represented are William Bartram, Frederick Pursh, Pierre Turpin, and Benjamin Henry Latrobe.

This is a collection of letters, letterbooks, account books, scrapbooks, etc., concerning the families of Robert Hare and Thomas Willing. The letters and other documents include early family material, as well as documents written by numerous family relations, and some obviously only collected by them. The Willing family letters (1744-1901) are diverse, concerning family matters, business, society, comments on the Civil War, etc. There are numerous letters from Thomas Willing, many concerning his banking career, as President of the Bank of North America and later at the first Bank of the U.S. The Hare family letters (1724-1965) are more extensive and diverse, including much on travel in the U.S. and elsewhere. There is a letter from Robert Hare Jr. concerning steam engines, and letters from Horace Binney Hare concerning his education at Harvard, 1860, his trip to San Francisco and the west, 1862, and numerous letters written while a soldier in the Civil War. There are many letters from Horace Binney (1780-1875, DAB) to his daughter Esther, who was married to John Innes Clark Hare (1816-1905, DAB), concerning family travel and court cases. There are also letters from outside the family, such as those from Dorothea L. Dix. The bound volumes include, among others: Robert Hare letterbooks (1824-1825, 1841-1857), estate records, and laboratory expense accounts (1818-1860); G. H. Hare's journal or log of cruises aboard the U.S. United States (1841) and U.S. Flint (1845); Horace Binney Hare's 1862 journal of his trip to San Francisco. There are account books and accounts (1754-1795) kept by Thomas Willing; accounts of the controversy over the estate of John Innes Clark; and records of the First Colored Wesley Methodist Church of Philadelphia (receipt book, 1820-1848; minute book, 1827-1844). There are also Philadelphia court records, and minutes of the Common Council of the city, 1832.