Some radical ideas follow. Remember, they are just that... ideas. Some may see them as blasphemous or traitorus. Understand that I love the USA and am grateful for the priviledged life it enables me to live. I bear no malice towards any in the population or government. That being said...
Question: What is The significance of the year 1863?
Answer: Modern slavery was introduced to the USA.
There was no emancipation. It is no coincidence that the signing of the emancipation proclamation and the introduction of our current paper money system occurred the same year.
The native American population were not very competent slaves. They tended to die when captured and even if they survived, they weren't very energetic, nor responsive to physical coercion. As such, the Europeans were forced to import their slaves from Africa.
The boat ride over was no party... the life they lead was not much fun either. The conditions were so harsh that only those with exceptional endurance and strength survived. The resulting population grew strong. The owners realized that by breeding for strength they could achieve greater efficiency from their slave population as well. So on top of the natural selection, purposeful selection further enhanced the slaves' abilities.
I didn't take long for the slaves to notice that they could kick their owners asses at will. Those non-compliant slaves quickly learned the difference between a beating and a shooting. Guns. Guns were the only reason slavery was sustainable at all. Well, guns and the fact that the slaves didn't have any. Still the sheer numbers of slaves made for a management problem. Well, the owners figured, "If we can breed for strength, we can breed for docility and/or intelligence too." Nigger can read - dead. Nigger says, "Duh." a lot - He's making babies.
So life went on with the numbers of dark skinned workers constantly growing, the population growing ever more physically gifted, a little more compliant, and a bit duller around the edges. There were a few other, unexpected characteristics being promulgated in the slave population as well. ...No, I'm not talking about big dicks... though it does count in this section...
A the ability to maintain 2 cultures with a single population. The the public culture, which interacted with the white people and could be seen in the public at large. Then there was the private culture. This is where intelligence and creativity were kept alive in spite of the owners breeding efforts. Sets of skills and concepts became verbal legacies past down through generations. An example:
Determining what a person's dreams and desires are and then how to feed those dreams and desires back to them and manipulate them to get what you want.
The wealth generated by free labor was (is) fantastic. So much so, that the Americans imported as many slaves as possible. The slave population grew rapidly and large.
Perhaps the printing of The Origin of Species highlighted the weakness in their slavery system... A very large and powerful population of people, full of justifiable hatred, was living in the backyards of the ruling class. Any more growth in their numbers and they would become unmanageable, in fact, signs that they were already unmanageable were quite common. It was only a matter of time before a grand revolt was successful. Regardless, more workers were needed to sustain growth. A change was necessary...