The passage of the First Confiscation Act by Congress in August 1861 created a problem. While the law was popular in the North, as it deprived rebels of their slaves if they could reach Union lines, it also created a problem. The law left the exact status of confiscated slaves uncertain. While effectively they were no longer slaves, neither were they free.
For the next year, the fate of the “contraband of war” was a matter of considerable debate. While there was widespread support for the idea of confiscating the slaves of disloyal owners, especially since they were a militarily valuable resource that could be put to use for the Union, much disagreement existed in the North about what would become of these slaves.
Abolitionists, of course, demanded that confiscated slaves be freed. This argument had appeal outside of abolitionist ranks because slaves that made it to Union lines generally were treated as free once they arrived. They received wages for their work for federal forces, even if it was sometimes slow in coming. Although the slaves generally stuck close to Union-controlled areas for fear of being recaptured by the Confederates and returned to their owners, usually their movement was restricted no more than other civilians.
Still, opposition existed in the North to the idea of simply freeing confiscated slaves. For one thing, it was not clear whether Congress, especially in light of the Dred Scott decision, had the constitutional authority to confiscate rebel property, let alone to free the slaves of disloyal masters. It also was arguable that confiscation represented a bill of attainder (legislatively dictated punishment), which was explicitly prohibited under the Constitution. There was also a hope in the North among many people that the war might be ended by a negotiated settlement that brought the seceded states back into the Union. If such a settlement occurred the slaves became bargaining chips, with their return to the owners a likely condition of reunion.
But as 1861 turned into 1862, and the cost and casualties of the war mounted opposition to the idea of freeing the slaves waned. A negotiated settlement became increasingly unlikely, and the idea grew that without an end of slavery, even if peace were some how restored with slavery intact, there could be no lasting peace between North and South.
Senator Lyman Trumbull introduced what would become the Second Confiscation Act at the start of the congressional session in December 1861. Trumbull saw it through the Judiciary Committee, which he chaired. The bill was helped along on the floor of Congress by the disastrous Peninsula Campaign in the late spring/early summer of 1862, where George McClellan failed to take Richmond. Besides stoking the anger in Congress for the rebels, it led to the realization that there would be no quick end to the Civil War and radical measures, like freeing the slaves, would be required. President Lincoln, who although not publicly embracing such sentiments, privately was already circulating a draft the preliminary Emancipation Proclamation among his closest advisers, signed the bill into law on June 17, 1862, 150 years ago today.
The full text of the Second Confiscation Act can be found at: http://www.history.umd.edu/Freedmen/conact2.htm.