Through widespread and relentless surprise attacks and ambushes, Confederate guerrillas drove Union soldiers and their leaders to desperation. Confederate cavalrymen engaged in hit-and-run tactics; autonomous partisan rangers preyed on Federal railroads, telegraph lines, and supply wagons; and civilian bushwhackers waylaid Union pickets. Together, all of these actions persuaded the Union to wage an increasingly punitive war.  Drawing upon the guerilla attacks and Federal responses over a broad range of operational theatres, Dr. Mountcastle presents a new look at the complex nature of guerrilla warfare in the Civil War and the Union Army's calculated response to it.   As the problem grew throughout the South, Union commanders were ultimately convinced to adopt retaliatory measures that challenged the sensibilities of even the most hardened soldiers.