John Singleton Mosby's Rangers bedeviled the Union army for four long years. The Rangers were what we would today call guerillas; units that could make fast raids and get away before the enemy could react. This highly-successful unit became legendary during the war and continues to be an object of fascination by scholars and enthusiasts of the period into the 21st century. This is the official memoir of Mosby's command, written with his cooperation after the war. The author of this work, John Scott, wrote the Partisan Ranger Law in 1862. John Singleton Mosby was a remarkable individual. Highly intelligent, educated, and modest, he held the respect of many on both sides of the war. After the Civil War, he became a Republican and a supporter of Ulysses S. Grant.