I feel as though I ought to write two (or three) reviews of this book, because it consists of two (or three) stories: the creation of the Columbian Exposition of 1893, the murders committed by H.H. Holmes, and (peripherally) the assassination of Mayor Carter Harrison.

Larson's narrative jumps back and forth between these stories, without ever connecting them, and so the book leaves one with a very disjointed feeling, a feeling that something was left out, something that would show a relationship among the events described (or at least one more significant than that they occurred in the same city at the same time).

The book is worth reading for the history of the Columbian Exposition. Such an enterprise naturally left a great deal of source material for Larson to draw on, and he wisely chose to focus on the involvement Daniel Burnham and Frederick Law Olmstead, the planner and the landscape architect. Both were not only interesting, brilliant men in their fields, but were inveterate diarists and letter writers, very helpful to the historian! It's a great saga, as Chicago is awarded the Fair with less than two years until its planned opening. Even though one knows, of course, that the Fair went off magnificently, one is on tenterhooks reading of the rivalries, the missteps, the difficulties. Will it open? Will it be ready? Excellent stuff.

The story of H.H. Holmes, serial killer, who lured young women to his oddly-constructed building near the Fair and gruesomely killed them, on the other hand, is badly told and unconvincing. Why so? The source material, for one, is lacking. Though Holmes wrote a memoir, and Larson also consulted the trial record [of H's murder trial in Philadelphia; he was never charged with the murders in Chicago] and contemporary news accounts, the author seems to rely heavily on a couple of sensationalist books whose sources are not sufficiently accounted for. Naturally, one must take with a grain of salt the hindsight memories of those who, after Holmes' activities were known, "always thought there was something odd".

Larson also has an annoying habit, one which he shares with some other writers of non-fiction, of engaging in speculation and interpretation presented as fact. He describes thoughts and feelings of real people with no basis other than "it's likely". The difficulty is that the text is presented with no qualification, and it is only careful attention to the endnotes that reveals Larson's imagination is at work.
I'm not sure why he felt the need to weave in the thread about Harrison's assassination, other than the fact that it occurred a few days before the close of the Exposition and so affected the closing ceremonies. It was a curious event in Chicago history, the assassin was clearly a paranoid schizophrenic, but it doesn't contribute much to this history.

On balance, the book is good reading for the sections on the Exposition (and should be in any collection of Chicagoiana for that), and even the rest of it is somewhat redeemed by Larson's generally compelling narrative style.