During the American Civil War, federal scouts served as Union spies who traveled ahead of the other troops to gather information about Confederate troops. The term can refer to a variety of roles, from undercover agents to soldiers who simply kept a lookout.
Both the Union and the Confederacy had scouts who served similar roles, but the term "federal" means that the scout was working for the Union. Some scouts wore military uniforms and simply rode ahead of the rest of the troops to make sure the way was clear. They also looked for secure locations to camp or tried to find the best battle positions.
Other scouts were more similar to modern undercover spies. Some even wore Confederate uniforms and tried to learn secrets about Confederate strategies and plans, which they would then report back to Union military leaders. Many scouts served in both roles, although they were often referred to as scouts while in uniform and spies when they were in civilian clothes or the enemy's uniform. Scouts also performed acts of sabotage, such as destroying bridges to hamper the enemy's movements.
Some scouts were not in the military. Women were especially likely to serve as unofficial scouts and spies. These women would provide material support, such as food and shelter, to Confederate soldiers, or they would be socially involved with the enemy.