Gen. David McMurtrie Gregg (1833-1917) was one of the ablest and most successful commanders of cavalry in any Civil War army. Pennsylvania-born, West Point-educated, and deeply experienced in cavalry operations prior to the conflict, his career personified that of the typical cavalry officer in the mid-nineteenth-century American army. Gregg achieved distinction on many battlefields, including those during the Peninsula, Chancellorsville, Gettysburg,...