This popular work contains genealogies of the first families who settled in Pennsylvania between the Blue Ridge Mountains and the Alleghenies, and genealogies of those families who migrated across the Ohio River and made the first settlements in the Northwest Territory, now part of Ohio. About 350 families are listed in alphabetical order, with records of the first immigrant settler, including place and date of birth and death, place of residence, name of wife and date of marriage, names of children and their dates and places of birth, and names of grandchildren and great-grandchildren.