AllanD didn't nail it and the north wasn't treating the south in the manner you indicate. The industrial revolution was still a good way off--several decades--and most northern boys were farmers, just like the southern boys. It was Abraham Lincoln's idealistic view of preserving the union that drove the entire thing. Without this ugly, charasmatic man that stood physically a foot taller than everyone else, there would have been 2 countries. And it's entirely possible they would have rejoined again at some point.
Just because the Gettysburg address was belated doesn't mean it was irrelevant. Who can know what drives someone. Over-analyzing things is academic--there are things that you can devlope good theories for but then forget that your theories are wrong because you can't know what is driving a man as much as Abraham Lincoln was driven. He was a master orator when microphones and things didn't exist. he also didn't have the face time with people that we have now with televisons and such. People in the north voted to stay in the war by re-electing him. They were not swayed by his cool hair--they were swayed by their own gut feelings.
Without us being one country, I doubt we would have been effective in the last minutes of WW1 or throughout the 20th century. We may not have perfect individual rights, but without us being unified, we might not have any. WW1 had nothing to do with us at the start, and neither did WW2. Could half or 2/3 of the USA have been strong enough to build Russian equipment while they moved their industry over the Urals? Could 2/3 of us have fielded the 110 aircraft carriers we had at the end of WW2? The south, if independent would have been like Ireland during WW2. A neutral, noncommital pain in the ass because of their fear of the north's intent.
I don't know what the world would be like without Lincoln as the 16th president but it would be hard to paint a scenario where it's better. The implications are far reaching. For instance, without the united states, would all of the immigration have taken place? I doubt it. Some certainly, but not all. With immigration, we have more people of many nationalities living here than actually live in their own countries. Without immigration to fill up this place it would cost you $100 to find someone to walk your dog, let alone man the arsenal of democracy.
Welcome Visitor! Please take a few seconds and 
