With the chaos of the war, a working postal system was more important than ever for the Confederacy. The Civil War had divided family members and friends and consequently letter writing increased dramatically across the entire divided nation, especially to and from the men who were away serving in an army. Mail delivery was also important for the Confederacy for a myriad of business and military reasons. Because of the Union blockade, basic supplies were always in demand and so getting mailed correspondence out of the country to suppliers was imperative to the successful operation of the Confederacy. Volumes of material have been written about the Blockade runners who evaded Union ships on blockade patrol, usually at night, and who moved cargo and mail in and out of the Confederate States throughout the course of the war. Of particular interest to students and historians of the American Civil War is "Prisoner of War mail" and "Blockade mail" as these items were often involved with a variety of military and other war time activities. The postal history of the Confederacy along with surviving Confederate mail has helped historians document the various people, places and events that were involved in the American Civil War as it unfolded.