Sanity vs. Insanity
Devil in the White City tells the story of two men: Burnham, who found success and fame through his architectural prowess, and H.H. Holmes, who found infamy through a string of violent murders. Throughout the novel, these men are described using strangely similar phrases and wording. Both Burnham and Holmes’ eyes are described as being bright blue at multiple points in the book. The two men are ambitious and charismatic, doing whatever necessary to achieve their goals. What makes one sane and one insane is due to what those goals are. Through the descriptions of these two men, Larson shows how frighteningly small the gap between sanity and insanity is. He helps the reader see the ruthless cunning of the good Mr. Burnham, and the surface-level normalcy of many of H.H. Holmes’ actions.
How Actions form Perception
The descriptions of Burnham and Holmes’s personalities show how similar the two men could be. However, these two men stand on very different sides of history. One’s legacy is enshrined in fame, the other's is shrouded in infamy. This is not necessarily due to their personality traits, but to their actions. While Burnham used his intelligence, cunning, and ruthlessness to build a world-renowned fair, Holmes used those very same traits to murder innocent people. Larson shows that it is the actions that make the man, and give him his place in history.
Coexistence of Good and Evil
The book centers on the Chicago World's Fair and on how two very different men shaped its legacy. Intertwining the story of a "good" man and an "evil" man shows how each lived in the same space and time of history, walking very similar paths. Chicago in the Gilded Age was a hotbed of activity as its population and world standing rapidly increased; the creation of the modern skyscraper, the grandest fair the world had yet seen, and four violent deaths a day all occurred in 1890s Chicago. Burnham and Holmes’ stories show the two sides of this era, good and evil, and how they both lived in and thrived off of the city’s climate.
American Pride
It's not just Chicago's pride and identity that is at stake here, though Larsen ably indicates how important the fair's success was to the city; rather, it is America's pride and identity that is at stake. Paris had carried out a tremendously important and stirring exhibition that demonstrated to the rest of the world its preeminence in iron and steel and art and commerce. Its Eiffel Tower was a potent symbol of the city's grandeur and allure, and it was commonly assumed that nothing could equal or surpass it. Thus, Burnham and his associates knew that they had to create a fair that would show just how civilized and advanced America was, and if they did anything less than that, America's reputation would languish on the world stage.
Race and Empire
Even though Larsen doesn't explicitly deal with these themes, they are present in the penumbras of the text. The fair displays the supremacy of the Anglo-Saxon race and relegates other races to more primitive evolutionary moments. It touts the virtues of Western civilization, Christianity, and capitalism, encouraging visitors to buy things, feel proud of their country, and revel in their own advanced position, even if they are otherwise poor. Exhibits and representations of Native Americans or colonial peoples exoticize and "Other" them, putting them in veritable zoos for the consumption of the American tourist. The fair is thus an exemplar of the Gilded Age value of American supremacy, which would manifest itself not long after in the Spanish-American War.
Utopia
The White City of the fair is a sort of utopia, a promise of what a city could be but what it most certainly is not yet. It is clean, beautiful, sanitary, and safe; there are social services and public utilities, not to mention intellectual and artistic stimulation and numerous entertainments. People behave and move about in an orderly fashion. They are taught certain lessons about civilization even if they aren't aware they're being taught, and they, ideally, gain in civic virtue and character. A utopia is impossible, however, and the transience of the fair reinforces that reality. Thankfully, some of its aspects, especially with water, sanitation, etc. live on even after the White City falls into flame and dust.
Perseverence
If there is one character trait Burnham exhibits above others, it is perseverance. The undertaking he has signed up for is massive in its scope and potential significance, fraught with numerous opportunities to fail, and one that must be accomplished in an incredibly short amount of time. Burnham has to deal with procuring the talent he needs and showing them his vision; with squabbling politicians and architects; with bad weather and natural disasters; labor strikes and an economic downturn; with a punishing timetable; and much, much more. He's not perfect, of course, and often loses his patience or has to call on his position of authority to run over obstacles in his way. He is aware of the stakes and does not lose faith in his ability to pull the fair off, even as he acknowledges to himself how hard this is.