Seth Grahame-Smith's first work. Pride and Prejudice and Zombies, was a surprise bestseller combining about 85% of the original Jane Austen novel with ultraviolent zombie mayhem. Elizabeth Bennet is a highly-skilled zombie killer, as are her sisters, and it is by this yardstick that she judges Mr. Darcy and initially finds him wanting. There are some memorable scenes, such as when Elizabeth is traveling by foot on her way to aid her sister and is attacked and despatches a number of zombies. After the battle she kneels in a glade in the wood, rear back her head and keens her triumph. Definitely something you'd imagine Jane Austen's contemporaries doing.
Now Grahame-Smith has, through a series of unusual events, come into possession of Abraham Lincoln's personal journals. Long suspected but never found, the journals detail Lincoln's life as a vampire hunter (for it was a vampire who killed his mother and ruined his father) and how slavery itself was a means by which vampires were able to thrive in the United States. It is with this knowledge that we have a greater understanding of his actions as President: to rid the country of vampires he first had to rid the country of slavery.
There are many surprise appearances, most notably that of Edgar Poe, and twists and turns--enough to make the book enjoyable although sometimes it takes on the qualities of a bloody laundry list (kill this vampire, kill that vampire, kill another vampire). But on the whole the novel turns vampires on their head, so to speak. Once turned, they take some time getting re-acclimated to sunlight but eventually can walk out in the daytime. Their eyes are black and have no pupil, so they tend to wear dark glasses to cover that flaw. And one drop of their blood can cause people to die (the "milk sickness" supposedly caused by drinking tainted milk), rather than become vampires themselves.
Whether one fully buys the Lincoln-vampire-slavery premise or raises a few concerns about trivializing an epic American event (and fiction can only work if one fully suspends disbelief), it is certainly a great mash-up of history and horror. The pictures alone, detailing Abe's life as well as vampire society, are amazingly well-done.