Symbolism, Imagery, Allegory
In ancient Rome, the Colosseum was the site of countless bloody battles and many moving speeches made by Russell Crowe.
Early Christians and slaves were sacrificed at the Colosseum. Now, it's Daisy whose innocence is laid on the altar of a great empire. Okay, in Daisy Miller, the blood that's being shed is not quite so literal, but it still has fatal consequences. The "wound" that leads to Daisy's death is inflicted in the Colosseum—it's there that she contracts malaria and also severs herself from Winterbourne most definitively.
This casts her in the position of a sacrificial victim to a few different things. Firstly, male power relations. Sometimes we wonder, is this really about Daisy, or is it just some weird pissing contest between Winterbourne and Giovanelli? Winterbourne's insistence that he's the real gentleman and Giovanelli is just a fake seems a little too big of a deal to leave us feeling like it's all about Daisy.
Secondly, nationalistic identity crises. Winterbourne has this casual relationship with an older (hint: Old World) European woman and then the American Daisy comes along all fresh and new (hint: New World) to make him question what he really wants and needs in a woman (or a nation). Since Daisy dies and Winterbourne goes back to his Swiss temptress, we feel pretty confident that little Daisy from the US of A is the one who gets the short end of the Winterbourne stick. That's a win for Europe.
Lastly, Daisy is sacrificed for a lot of class anxiety. The Americans in Rome are pretty sure of their place in America, but when they're in Rome, things get a little mixed up. New money people like Daisy come to town and get into society way more quickly than they ever would back in New York—that's part of the reason why they go to Europe in the first place. Making Daisy feel like she's inferior is how the old money people still get to feel like they're superior—and that's one heck of a sacrifice for our girl Daisy.
We know that's a lot to fit into the Colosseum, but we can assure you of one thing: the place is huge.