The Mississippi River, the second longest in the US, played a decisive role in the American Civil War. The Confederate fortifications were put to the test in the lengthy Federal campaign of 1862-63, aimed at cutting off the Rebel states of Arkansas, Louisiana and Texas and creating a blockade of this trade route. Vicksburg was a fortress city, known as the Gibraltar of the Confederacy; the initial Federal attack on May 19, 1863 failed to take the city, and a state of siege ensued, which saw the creation of a complex system of trenches, tunnels, mines, and batteries to invest the place. This book examines these and other sites, and the role they played in the war.