NONFICTION - Dec. 30, 1990

MOSBY’S RANGERS by Jeffry D. Wert (Simon & Schuster: $22.95; 384 pp.) John Singleton Mosby, probably the most famous guerrilla leader of the Civil War, wrote in the 1880s that “the military value of a partisan’s work is not measured by the amount of property destroyed, or the number of men killed or captured, but by the number he keeps watching.” Mosby, commander of the rag-tag 43rd Battalion of Virginia Cavalry, better known as Mosby’s Rangers, kept many Union soldiers watching for more than two years, and historian Jeffry Wert shows exactly how. Mosby’s campaign of harassment, consisting of surprise attacks on Union detachments, high-ranking officers, and supply trains only miles from Washington, was remarkably effective; he lost few men, and rattled the Union command so much that it once believed he was planning to kidnap Abraham Lincoln.