The house where George Washington was born had long ago gone to ruins by 1816, when his adopted son George Washington Parke Custis sailed to Pope’s Creek in Virginia and laid a stone near the spot. Unmarked a few dozen miles to the west, Custis bemoaned, lay the grave of the woman who brought Washington into the world. Even today, no historian can precisely say where lies the body of Mary Ball Washington.

To the noble undertaking of unearthing the mother of the father of his country comes biographer Craig Shirley with his new book, Mary Ball Washington. Famous for biographies …