It happened like this...
Booth's gun backfired/malfuntioned?
If John Wilkes Booth's gun, that was used to kill Lincoln, malfunction or backfired what do you think would've happened in the theater next? Obviously chaos would erupt in such a situation due to the sudden outburst, but depending on the malfunction of the gun, Booth could've died on the spot and everyone would've assumed it was a public suicide for the President as Booth could've been trying to send a message. I think it's safe to say, if Lincoln wasn't killed that evening, our President would've continued his plans for our country and execute them properly.
Obviously the Presidents security will greatly increase after an attempted assassination and frighten U.S. citizens by having them know how close they were to loosing a President. If Lincoln survived that night and knew how close he was to being shot, would that fuel him and the United States to keep fighting and have the war keep going on? Unfortunately Booth's gun didn't backfire or malfunction which would've saved our 16th President as he was murdered that night.
Slaves never came into america?
Eventually Blacks will come into the picture but I believe our country would be able to handle the situation better than it was handle over 150 years ago. When our country would finally re-attempt to find slaves do you think they would use them the same way they actually were used or do you think that they wouldn't even view them as slaves? If segregation was never a factor and our races met at a natural & neutral peace do you think that we would have more problems now from all the built up minor factors of being at a major peace and love era?
The 16th President of the United States of America.
John Wilkes Booth
An actor and the murderer of Abraham Lincoln.
People/Minorities forced to work for no pay and little food who can be abused by their owners at any point.