Created in 1772, Northumberland County was the parent county of twnety-seven Pennsylvania counties. The wills and administrations given in this work are abstracts of the records of Northumberland County and three of its offspring: Northumberland County from 1772 to 1813; Mifflin County from 1789 to 1793; Union County from 1813 to 1818; and Indiana County from 1818 to 1849. The abstracts are arranged by county and are therein divided into separate sections of wills and administrations. The latter typically provide the exact date of administration, name of the deceased, names of administrators, and names of sureties, while the former provide the exact date of probate, name of the deceased, name of town or township of residence, and names of heirs--usually family members. The arrangement of data in each section is chronological, but there is an index to decedents to help the researcher over the main hurdle. Approximately 10,000 persons are mentioned in the text.