Sweep the Shenandoah Valley clean and clear, Union General-in-Chief Ulysses S. Grant ordered in the late summer of 1864.His man for the job: Maj. Gen. Little Phil Sheridan, the bandy-legged Irishman who d proven himself just the kind of scrapper Grant loved. Grant turned Sheridan loose across Virginia s most vital landscape, the breadbasket of the Confederacy.In the spring of 1862, a string of Confederate victories in the Valley had foiled Union plans in the state and kept Confederate armies fed and supplied. In 1863, the Army of Northern Virginia used the Valley as its avenue of invasion,...