A remarkable history of First Lady Michelle Obama's mixed ancestry, American Tapestry by Rachel L. Swarns is nothing less than a breathtaking and expansive portrait of America itself.

In this extraordinary feat of genealogical research--in the tradition of The Hemmingses of Monticello and Slaves in the Family--author Swarns, a respected Washington-based reporter for the New York Times, tells the fascinating and hitherto untold story of Ms. Obama's black, white, and multiracial ancestors; a history that the First Lady herself did not know.

At...