This feud was sparked by the death of Charlotte Augusta Gibbes, stoking tension between her daughter-in-law and sister-in-law. For 10 points each:
[10h] Name or describe this high-society feud between Caroline Schermerhorn and Mamie Paul, whose bitterness culminated in Mamie’s husband constructing a 13-story building next to Caroline’s mansion out of spite.
ANSWER: “Mrs. Astor” feud [accept answers mentioning a feud over who would receive the title “Mrs. Astor”; prompt on Astor]
[10e] William Waldorf and Caroline Astor built rival examples of these buildings which eventually merged into a single one. Henry Hardenbergh designed those buildings as well as the “Plaza” one overlooking Central Park.
ANSWER: hotels
[10m] A Ward McAllister list, as dictated by Caroline Astor, suggested that only this number of people in New York “mattered.” That list of this many people inspired a (emphasize) larger number in the title of an O. Henry book.
ANSWER: The Four Hundred (The O. Henry book is The Four Million.)
<Strombeck, Other Academic>