Witmer Stone was born in Philadelphia, Pennsylvania, on September 22, 1866, to Anne Eveline (née Witmer) and Frederick Dawson Stone. According to longtime friend, Cornelius Weygandt, Witmer Stone was “of the Chester County Quaker-Pennsylvania Dutch cross that has given us so many of our botanists and ornithologists, paleontologists and chemists.”Weygandt, Cornelius. Philadelphia Folks. D. Appleton Century Co. 1938. Stone showed an early interest in all things natural, and was an inveterate collector. Stone was a boyhood friend and schoolmate of two of the Brown brothers: Amos Brown later became a geology professor at University of Pennsylvania, and Stewardson Brown became the Curator of the Department of Botany at the Academy of Natural Sciences of Philadelphia. Stone and his brother, Frederick, and three of the Brown brothers formed the “Wilson Natural Science Association”, named in honor of the pioneering American ornithologist Alexander Wilson. Stone also spent time exploring the woods and fields around his grandmother's Chester County, Pennsylvania home. Stone married Lillie May Lafferty on August 1, 1904; they had no children.
