Answer: Books on Pennsylvania history
Abraham Harley Cassel (1820-1908) was a book collector and historian who in his lifetime acquired over 50,000 books, pamphlets, and documents about Pennsylvania history. Cassel was born in 1820 to German-speaking members of the Dunkard Church, Yelles and Mary Harley Cassel, in Towamencin Township in Montgomery County, Pennsylvania. His mother was the great-granddaughter of Christopher Sower (or Saur), an early book printer in Germantown, Philadelphia, and was also descended from Peter Becker, the first minister of the Church of the Brethren in the colonial United States.
Cassel received little formal schooling as a child and primarily worked on his family's farm. He fed his love of learning in secret, reading by candlelight after the rest of the family was asleep and teaching himself English from a pocket dictionary. Despite these obstacles, in 1840 Cassel became a successful school teacher. He eventually formed a family and moved back to run his family's farm. Cassel welcomed the freedom of farming as it gave him to read and study every day, as well as develop his library. In addition to this work, Cassel also increased his reputation as a historian through his writings. In 1852 Cassel began to write about the history of the Church of the Brethren for church periodicals and became known as an expert not only on Dunkard history, but also the religious, political, and social history of Pennsylvania Germans. His library in Lower Salford became a destination for everyone, from historians to teachers to politicians.
The Abraham H. Cassel collection (#1610) at HSP contains a selection of printed material from his library, including volumes relating to the Ephrata religious community and the Schwenkfelder Church There are hymn books, religious tracts and catechism, diaries, letters, genealogical records, and examples of Pennsylvania German folk art and fraktur.