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.

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.