Harriet Verena Evans was born in Lancaster, Pa., on April 28, 1782, the daughter of John and Sarah Musser. On May 21, 1807, Harriet married Cadwalader Evans (1762-1841), a former surveyor who went on to a distinguished career in politics, as one of the directors of the Bank of the United States, a promoter of the Schuylkill Canal, and president of the Schuylkill Navigation Company. The couple had nine children, including a set of twins. The diary of Harriet Verena Evans is an unusual example of a woman's spiritual diary from early national Philadelphia. Beginning on her 46th birthday in 1827, the same day her seventeen year-old son John died, Evans made sporadic entries in her diary for seventeen years, marking birthdays, holidays, special events, and anniversaries of various kinds. Fixated upon praying (or fretting) over her spiritual state and future, Evans continued to mourn over John's loss for many years, remembering him regularly on the date of his birth, death, and burial. She was also particularly prone to composing (or copying) religious poetry, and in sections, the diary verges on a poetical commonplace book. Other entries reveal Evans' concern for her other children, three of whom were students at the University of Pennsylvania, and on July 25, 1832, she made a particularly long entry discussing the arrival of the cholera in Philadelphia.

This collection includes letters, diaries, notebooks, and early photographs, relating primarily to the Wister family of Germantown and Philadelphia. Much of the correspondence concerns domestic news and consists of letters from or to Sarah Wister. These include interesting observations on Germantown and Philadelphia society from other families as well, such as the Bayntons and Bullocks. There are numerous letters from various Wisters, including Casper, Charles Jones, Elizabeth (including a journal of a trip to Bristol, 1783), Hannah, John, Owen Jones, and others. There is also poetry by Sarah.

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.