Although the victory of the North resulted in the end of slavery, that was not the stated aim of either President Abraham Lincoln or the industrial bourgeoisie that was the dominant social class in the North when the war commenced. The war began only as a result of the decision by most of the “slave states” to secede from the Union in 1861.
Lincoln refused to end slavery, assuring all slave owners who cooperated with the federal government that they would maintain “their property.” His eventual decision to issue the 1863 Emancipation Proclamation, which decreed the end of legal slavery, was fundamentally a military decision.
Without the enlistment of thousands of escaping slaves into the Northern army, the defeat of the Confederate army seemed remote. These newly enlisted Black soldiers, with their incredible resolve, determination and self-sacrifice, turned the tide. It was a case of law following reality: Slaves were deserting or refusing to work on the plantations in growing numbers, and they were demanding the right to join the battle.
The military exigencies of the day overcame the white supremacist policy of the Northern army and the federal government, which had refused to abolish slavery until that time.
The Emancipation Proclamation had the effect of drawing into the struggle the Black masses—and it proved decisive. African Americans comprised a social class rooted in the slave system itself, and ultimately determined the outcome of the Civil War. After the proclamation, some 180,000 freed slaves enlisted in the Union Army and became fearless fighters against the army of their former masters.
When Confederate General Robert E. Lee surrendered in 1865, the question of how to reintegrate the Southern states into the Union was sharply posed. This was the basis for the period of Reconstruction. It represented a continuation of the conflicts of the Civil War, but under new circumstances determining the direction of the life-and-death struggle between the overthrown and the overthrowing classes.
Like every revolution, the military conflict of the Civil War was followed by a period in which the remnants of the previous order were suppressed, both by political means and by force. The French Revolution, the 1917 Russian Revolution, the 1959 Cuban Revolution and others all relied upon extraordinary measures to survive and fight off the attempts of the former ruling classes to regain political power.
How to suppress these forces had been the subject of debate in the Northern political circles throughout the war. On the one hand were moderates like Lincoln who wanted to incorporate as many elements of the old slave-owning class into a new pro-Union government. On the other hand, Radical Republicans like Thaddeus Stevens and Charles Sumner favored harsh repression and exclusion of Confederate society from political power.