If you're quoting something, please make sure you're doing it correctly. It's from "Pride and Prejudice". Here's the correct quotation:
<<Elizabeth Bennet had been obliged, by the scarcity of gentlemen, to sit down for two dances; and during part of that time, Mr. Darcy had been standing near enough for her to hear a conversation between him and Mr. Bingley, who came from the dance for a few minutes, to press his friend to join it.>>
It makes much more of as sense now because one of the meanings the word 'oblige' has is to force or to make. In other words, Elizabeth Bennet had to (had been obliged / forced / made) sit and wait two dances because there were not enough dance partners.