Actually Not a Vampire: A funny shortened version where Abe and Edgar Poe meet on the street and mistake each other for vampires (because of the way they were dressed and for recognizing another man who actually was a vampire). Of course, they straighten things out and become friends.
All Just a Dream: A Running Gag. Basically, if the chapter opens with main characters being randomly killed by vampires, expect to shortly read "Abe awoke with a start."
Truth in Television: Lincoln was known for melancholy and dreaming of dire portents. He wrote in a note to his wife,
"Think you better put 'Tad's' pistol away. I had an ugly dream about him."
Bad Dreams: Abe suffers from these frequently, at least once proving to be prophetic.
Beethoven Was an Alien Spy: The book lives on this trope. Lincoln was a vampire hunter, Edgar Allan Poe was a vampire fanboy, the Roanoke colony was killed off by its vampiric doctor, and John Wilkes Booth was, you guessed it, a vampire.
Black Eyes of Evil: The vampires' pupils are dilated to the point that it looks like they have these.
Bloodier and Gorier than its contemporary vampire stories. But a lot of the carnage is unrelated to the vampires themselves with regular old-fashioned human-on-human war and murder being large parts of the book.
Daywalking Vampire: Sunlight burns the skin of young vampires, but after a few years they become immune. Their eyes, however, never become immune no matter how long they live, so they have to wear sunglasses in daytime.
Eye Scream: The above vampire infantry are described having mutilated several men, including poking out a drummer boy's eyes.
Females Are More Innocent: Averted. Abe seems to think this at first, incredulous that one woman is a vampire (expecting it to be her husband), but quickly learns better.
Which is strange, considering the first vampire he comes across while hunting is a woman who kidnapped and murdered children.
Footnote Fever: Grahame-Smith uses footnotes to explain places and terms that readers might not know, references for quotes (usually the Bible or William Shakespeare), or how recorded history got some actual event wrong.
Foreshadowing: The aforementioned dream sequences have a lot of this.
Foregone Conclusion: Anyone who had to study American history in grade school knows how the war turned out and what happened to Lincoln, and all it takes is a quick internet search to find out the fates of most of Abe's family and friends.
Friendly Neighborhood Vampire: Henry Sturges. He is obliged to feed on people, but makes a point to only kill bad ones, or those so old or ill they're about to die anyway. As he puts it, 'All of us deserve hell, but some of us deserve it sooner.'
Heel Realization: Stephen Douglas when Lincoln tells him the vampires he was preaching for intended to enslave all of America, just like the blacks were enslaved to whites.
The Obi-Wan: Henry. Albeit the version who doesn't die.
Our Vampires Are Different: Most of them are at least tolerant of sunlight (the weakness fades with age), garlic has no effect, and their eyes turn completely black when they're about to feed. They can also do things like jump from one bank of the Mississippi to the other in one leap. Their existence is also known to many of those in power, and a faction of them is allied with the Confederate States of America.
Very Loosely Based on a True Story: While the concept is obviously ludicrous, Grahame-Smith supplements it with actual historical context and events as well as direct quotes from Lincoln himself. The brawl that led to Jack Armstrong befriending Lincoln? An amalgamation of testimonies based around the actual event. "The Suicide's Soliloquy?" Written by Lincoln. Lincoln's dream of his own funeral? A direct quote from the man himself.
War Is Hell: Shown clearly and graphically as well as outright stated.
Who Wants to Live Forever?: Early in his mentoring, Henry gives Abe a lecture on the disadvantages of being immortal, to explain why so many of his kind commit suicide in their third centuries. "Without death, life (becomes) meaningless. It is a story that can never be told. A song that can never be sung. For how would one finish it?"