Beginning with why many English Lords were in need of rich wives down to the practice of choosing American wives waning, this book tells a lot of the history both of the English upper class/nobility and of New York high society. I think there is a bit of a bias in favor of the English as the author clearly doesn't think much of New York high society of the late 19th century. If you're interested in seeing some color photos of dresses worn by New York society ladies, the Met Museum has a great photo collection of dresses by Worth.