With a title like Abraham Lincoln: Vampire Hunter, you kind of expect the novel to be tongue-in-cheek, action-adventure in the historical fantasy/fiction genre. However, what you get is a pretty dry textbook of an imagined alternate history that relates Lincoln's life but inserts vampires into the mix.
The textbook approach is evident in the constant POV switches: you get a paragraph or two of the author relating the story, then a paragraph or two copied from Lincoln's secret diaries (and/or actual historical documents). You never get very engaged with the story for this reason and the main character ultimately feels distant. Overall, the book reads like a dry biography with bits and pieces of action thrown in.
The novel is cut into three sections. The first one relating the early life of Lincoln, the second his most active vampire hunting years and the last one his presidency and the American Civil War. My personal opinion is that the story would have been a lot better if the author had focussed on the middle part instead of choosing to write a biography spanning Lincoln's entire life. As it is, the story skips over several years at a time, failing to grasp the reader's attention or interest in the character or in the relatively sparse action (sparse in relation to what the title of the novel leads you to expect, that is.)
The pages are adorned with several badly photoshopped photos of Abraham Lincoln and others of the era - mostly to insert an axe or some proof of vampires into them. These brought a smile to my face and show the potential for the sort of tongue-in-cheek humour that this novel could have done more with.
This is one of the rare novels where the film is actually better than the book that it is based on.
Title image from the film with the same name