Tactical or battlefield intelligence became very vital to both armies in the field during the American Civil War

American Civil War

The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...

. Units of spies and scouts reported directly to the commanders of armies in the field. They provided details on troop movements and strengths. The distinction between spies and scouts was one that had life or death consequences. If a suspect was seized while in disguise and not in his army's uniform, the sentence was often to be hung.