Character Analysis
No vampire hunter would be complete without his natural enemy, the vampire hunter hunter. There's very little to like about John Wilkes Booth, except for the fact that his name is easily remembered. He's a very unlikely assassin, as the narrator points out:
On the surface, it made no sense. John Wilkes Booth had been called the "handsomest man in America." Audiences packed theaters all over the country to watch him perform. Women trampled one another to catch a glimpse of him. He'd been born into the nation's preeminent acting family, and made his professional debut as a teenager. (13.33)
The narrator constantly reminds us that Booth is a famous actor because whenever Booth gives some speech, we are told that he probably rehearsed that speech or move. (Since we're writing this in front of a mirror, we sympathize.) So, when George Atzerodt wants to pull out of the conspiracy, Booth gives a speech: "Booth launched into a stirring speech. […] Certainly it had been rehearsed for this very occasion" (13.32). And when Booth jumps to the stage after shooting Lincoln, he yells out "Sic semper tyrannis" (which is the motto of Virginia and means "Thus always to tyrants"—that is, "tyrants best step off"), and the narrator notes, "Like the speech to his conspirators, it was a moment he'd probably rehearsed" (13.73). So Booth is, above all, a guy who plays a role.
But there are at least three reasons Booth is more famous for killing Lincoln than for winning an Oscar for acting. (Well, four reasons when we add the fact that he died long before the Oscars were invented.)
Booth, the (1) Southern Sympathizer and (2) Vampire
There's not much to say about these reasons: John Wilkes Booth dislikes Lincoln both because Booth supports the South and slavery; and because Booth is a vampire. (Though it's not clear that Booth knows that Lincoln is a vampire hunter. He just hates Lincoln because Lincoln is destroying the South, which is where vampires have the best life.)
Booth, the (3) Man with a Destiny
Much more interesting is the third reason Booth decides to kill Lincoln: he thinks he's destined for greatness. As a young child, Booth's mom used to tell him that when he was born, she asked God for a sign and the "flames had suddenly leapt from the hearth of their fireplace and formed the word 'country'" (13.37). For Booth, that "country" means "the South"; and he fantasizes about being hailed as "the Savior of the South" for planning this assassination conspiracy (13.31).
Oh, the Irony
But that's not how it really turns out. Booth does succeed in killing Lincoln, though he breaks his leg in the escape and then gets turned in by a Virginian. So the very people who he thinks should love him (Southerners) actually turn against him. And instead of posters about what a great actor he is, we get posters like this one offering a reward for turning Booth in.
But then, instead of being killed by Federal soldiers, Booth faces one more ironic twist: he shot Lincoln for the South and for vampires, but it's a vampire—Henry Sturges—who comes to kill him. That's adding insult to injury for Booth—so much injury he almost doesn't understand it. Before Henry kills him, Booth yells out, "You would destroy me over a living man?" (13.111).