This work presents a genealogical and historical survey of both male and female lines extending from John Alexander (born c1700) of Lanarkshire, Scotland, to the 1870's. Following a brief introductory note detailing the family's early history in Scotland, the text is divided into four parts focusing on the descendants of each of John's children: Hugh, James, Rachel and John. His daughter Margaret died without issue. Part I, The Family and Descendants of Hugh Alexander, of Sherman's Valley, Pennsylvania, covers the families and descendants of: Margaret Alexander Hamilton of Harrisburgh, Pennsylvania;John Alexander of Little Valley, Pennsylvania;Mary Alexander Clark of Sherman's Valley, Perry County, Pennsylvania;David Alexander of St. Clair County, Illinois;Hugh Alexander of Tuscarora Valley, Juniata County, Pennsylvania;James Alexander of McKeesport, Allegheny County, Pennsylvania;William Alexander of Centre County, Pennsylvania;and, Emily Alexander Evans of McKeesport, Allegheny County, Pennsylvania. Part II, The Family and Descendants of James Alexander, of Kishacoquillas, Pennsylvania, covers the families and descendants of: Jane Alexander Brown of Kishacoquillas Valley, Pennsylvania;Robert Alexander, Esq., of Kishacoquillas Valley, Pennsylvania;Elizabeth Alexander Wakefield of Spencer County, Kentucky;John Alexander of Logan's Springs, Kishacoquillas, Pennsylvania;James Alexander of Spring Run, Kishacoquillas, Pennsylvania;Hugh Alexander of Stone Valley, Pennsylvania;Rachel Alexander Semple of Stone Valley, Pennsylvania;William Brown Alexander of Clearfield County, Pennsylvania;Rosa Alexander Taylor of Montgomery County, Ohio;and, Joseph Alexander. Part III, The Family and Descendants of Rachel Alexander Vance, of Martinsburgh, Virginia, covers the families and descendants of: Samuel Vance of Stone Valley, Pennsylvania;John, Alexander, and Joseph Vance of Ohio;and, Rachel V. Porterfield of Martinsburg, Virginia. Part IV covers the families and descendants of: John Alexander of Chambersburgh, Pennsylvania;John Alexander of Greene Township, Franklin County, Pennsylvania;and, Margaret Alexander. An appendix provides sketches of other Alexander families independent of those discussed in the previous sections.