Since women possess far too much common sense to participate in something as ludicrous as a duel, Lincoln was forced to accept Shields' challenge on his fiancee's behalf. And that was a problem, because Shields was an experienced marksman, whereas Lincoln had little experience in the art of remotely drilling holes in other humans. Abe did have two things going for him, though: A) he got to set the terms of the duel, and B) he was basically superhuman. Lincoln used those two things to his every advantage: The duel would take place in a tiny arena where the participants would be separated by a wooden plank (stepping over the plank would mean forfeiture), and rather than Shields' preferred weapon of choice (pistols), they would use fucking broadswords.
Lincoln's carefully planned-out terms had precisely the desired effect. When they arrived at the duel and drew their broadswords, Lincoln reached up with his Stretch Armstrong arms and sliced a branch out of the top of a nearby willow tree. And that was the only limb hacked off that day, because Shields immediately called off the duel without so much as a drop of blood spilled -- although some say there was a puddle of something around his feet that day.
"Your dick. That could've been your dick."
So, just how close did our great nation come to never being led by the Great Emancipator? In his own words, "I didn't want the damned fellow to kill me, which I rather think he would have done if we had selected pistols."
And so Honest Abe never had to worry about pistols again, and he and Mary lived happily ever after.