The plant physiologist and historian Rodney H. True (1866-1940) divided his career relatively evenly between the Bureau of Plant Industry in United States Department of Agriculture and the Department of Botany and Morris Arboretum of the University of Pennsylvania. A specialist in the physiological function of mineral nutrients in plants, True was active in his later career in the Philadelphia Society for Promoting Agriculture, the Pennsylvania Horticulture Society, and the Agricultural History Society. The True Papers consist of 6 linear feet of material relating primarily to the period of his career spent at the University of Pennsylvania. The collection contains roughly equal proportions of personal and professional correspondence, with a few diaries and research notebooks documenting his involvement with professional organizations and his interests in the history of his discipline.

Robert Maskell Patterson (1787-1854, APS 1809) was a professor of chemistry and natural philosophy at the University of Pennsylvania (1812-1828) and professor of natural philosophy at the University of Virginia (1828-1835). He was director of the U.S. Mint from 1835 to 1851. His father, Robert Patterson, was a revolutionary soldier, professor of mathematics at the University of Pennsylvania (1779-1814), and director of the U.S. Mint (1805-1824).