Booth's bullet grazes Lincoln but besides a nasty cut causes no damage, not even a concussion. What happens then?
Well, odds are reconstruction would have been much more bloody that it was in our history. It must be remembered that when Lee surrendered, that did not actually end the war. Yes, one of the largest armies surrendered and the government fled because it was along the line of march. But the war was far from over, there were still large forces roaming around the country, including those in Oklahoma, Texas, and even Alabama and Florida. However, the assassination so shocked even the Confederates that many CSA leaders rethought if the war should be continued or not. General Joe Johnston was actually the commander of the largest force in the Confederacy, over 90,000 men. He was intending to continue fighting in Tennessee and the Carolinas, but the assassination was one of the final things that pushed him to surrender. Even he realized that continuing the war would only make things worse, and with the fall of the CSA government he would have been killing people for a lost cause. And this would have made reconstruction an even more bloody affair. The US might well have resembled Yugoslavia post-Tito than the unified nation it is today.
