Just skip the House Divided Speech. See if I care. Your loss.
I will not dispute that Abraham Lincoln was a very intelligent and very articulate man. His writing is some of the finest I have ever read, and his reasoning seems quite clear and relevant.
But you can't prove something that isn't true no matter how flowery are your words or how lofty is your rhetoric.
The man deliberately started a war in which 750,000 people were killed and much subsequent destruction of both society and fundamental rights occurred.
Lincoln put the Federal Government on the course towards total dominance and that is why it has become the gargantuan monstrosity with which we are attempting to deal with today.
New York (Media and Finance) and Washington DC, currently have an outsized role in our lives because their power was consolidated by Lincoln's actions in that war.