The initial exclusion of African Americans from Union military service reflected the deep-seated racial prejudices that permeated Northern society and the political calculations of leaders who hoped to maintain support from border states where slavery remained legal. President Lincoln and his advisors feared that enlisting black soldiers would drive loyal slaveholding states into the Confederacy while alienating Northern Democrats who supported the war effort but opposed abolition. Secretary of War Simon Cameron initially rejected offers from free black men to serve in the Union army, declaring that the conflict was "a white man's war" that did not require African American participation.
However, the reality of military necessity and the actions of enslaved people themselves would soon override these political considerations and force a fundamental reconsideration of African American military service. From the earliest days of the war, enslaved people began fleeing to Union lines, seeking protection and freedom from advancing Federal forces. These "contraband" refugees, as General Benjamin Butler termed them, presented Union commanders with both an opportunity and a challenge: their labor could support Union military operations, but their presence also forced difficult questions about the war's ultimate objectives and the status of escaped slaves in Union-occupied territory.