Allegheny County in southwestern Pennsylvania was for many years a staging area of westward migration. Thousands of early pioneers passed through it and thousands more stayed. Representatives of many of these early settlers, perhaps the majority, are immortalized in this work in genealogical and biographical sketches. The sketches, numbering approximately 2,250 and naming a total of 50,000 related persons, generally treat subjects who were born in the early nineteenth century, with reference to immediate forebears of the late eighteenth century. The sketches typically mention the date and place of birth and marriage of the principal subject, the place of birth of his parents and often grandparents, sometimes the name of the first ancestor in America, and details of religion, education, military service, occupation, home, and residence. Our publication is excerpted from Part II of the History of Allegheny County, Pennsylvania, constituting the entire genealogical and biographical section of that work, i.e. pages 209-786. As the index references correspond to the pages in the original, those page numbers have been retained in the reprint.