For a three-act plot analysis, put on your screenwriter’s hat. Moviemakers know the formula well: at the end of Act One, the main character is drawn in completely to a conflict. During Act Two, she is farthest away from her goals. At the end of Act Three, the story is resolved.
Act I
Chicago is chosen as the host city for the 1893 World's Fair. Architect Daniel Burnham is ready to get to work right away, but the city doesn't seem to know where to put the fair.
Meanwhile, across the way, Dr. H. H. Holmes takes over a drugstore, marries a bunch of women, and purchases a plot of land to build a hotel. His hotel lures a very particular type of guest: young, single women who seem to disappear shortly after checking in.
Act II
Things start to look up for Burnham and the fair. The city finally decides on a location, buildings go up, and all sorts of inventions and exhibitions arrive. The Ferris Wheel is constructed and it's a major delight to fair-goers. Yet outside in the Black City, things look grimmer. Holmes' death trap hotel claims its victims, and he flees the city shortly after the fair comes to an end.
Act III
Holmes is arrested on charges of insurance fraud, and his Chicago murders are brought to light by detective Frank Geyer. Holmes is sentenced to death by hanging.
But let's not end on that bleak note: though the World's Fair was only in Chicago for a brief period of time, it introduced people to some pretty cool stuff like Cracker Jacks and zippers.