Final answer:
The term "contraband" referred to escaped slaves during the Civil War that Union commanders considered captured enemy property, which allowed them to retain these individuals to support the Union war effort without officially granting them freedom.
Step-by-step explanation:
During the Civil War, the term "contraband" came to be used by Union commanders to describe escaped slaves who sought refuge with Union forces. General Benjamin F. Butler first used the term at Fortress Monroe, arguing that these individuals could be considered contraband of war, similar to captured enemy property. This designation meant that while the escaped slaves were no longer bound to their Confederate owners, they were not officially recognized as free citizens. Under the protection of the Union army, contrabands performed vital labor such as building fortifications and providing logistics support.
However, their status remained undefined until wartime policies evolved, with initiatives such as the First Confiscation Act and eventually the Emancipation Proclamation, which dramatically transformed their fates and the structure of labor within the Union army.