What is the best summary of this paragraph? During the Civil War, intelligence was gathered in the same ways it had been gathered in previous wars. Photography and the telegraph were some of the technological advances that were used in Civil War espionage. Most espionage during the Civil War was fieldwork that included observation, scouting, and interrogation of prisoners. Enslaved persons that ran away, as well as prisoners from the Union Army, were good sources of information during the Civil War.