The assassination of Lincoln was a huge deal. It was experienced as huge at the time. But my guess is, they didn't know the half of it.
Here's the nub: the Civil War had just been concluded, and now it was time to "bind up the nation's wounds." But instead of Lincoln overseeing the post-war reconstruction effort, we had Andrew Johnson.
The evidence of history is that the overall healing of the wounds ended up very badly. Not just because of Andrew Johnson, of course. But his role seems more part of a profound national problem than of its solution.
In any event within a short time of the terrible war's conclusion, we see all the ugly forces that drove the defeated Slave Power regathering. The KKK and the violence and intimidation of "the Bloody Shirt" helped drive the South back into a form of racial terror and tyranny. The worst elements of the South prevailed.
Lincoln himself had great qualities of character, and by then also great stature, that could have helped drive out the darkness and allowed "the better angels of our nature" to prevail.
And I can readily imagine that, had Lincoln had the four more years in the White House to which he'd been elected, he might have been joined in such an effort by the person who represented all that was best in the South, and who also was, at the war's close, not only the region's most widely respected but also the most deeply revered figure: Robert E. Lee. In the wake of the war, Lee showed great character, and he used his influence toward reconciliation and healing. He was as devoted as Lincoln to those "better angels of our nature."
Imagine, then, Abraham Lincoln and Robert E. Lee leading their respective halves of the bloodied and divided nation onto a path of reconciliation. The rage and hatred and bigotry become subordinated. Under the impetus of their leadership, the patterns of violence and lying and resentment recede in power. Those "better angels" shape a very different society.
That imagining highlights one aspect of how history sometimes works: small things (like a single bullet) can produce big effects; history sometimes pivots on very diverse possibilities; big forces may generally govern, but the flapping of butterfly wings can sometimes change the pattern of the weather.
From there to the idea that had John Wilkes Booth been blocked from entry into the Presidential box at Ford's theater I might never have taken up my current work as a blogger, it takes one main step.
This insight --so I regard it-- has been an occasionally recurring theme in my writings over the past half-dozen years.
I'm not saying those forces are the ONLY ones operative. Surely, the drive of corporate capitalism to make the American government its wholly owned subsidiary is another component of what has happened. But, as I have argued here over the years in various essays, the patterns traceable to the political/moral/spiritual culture of the South are certainly a vital part of the core of that coalition that has channeled this dark spirit into power in America in our times.