The Age of Innocence, by Edith Wharton
I've never been much for American literature, so I've never read Edith Wharton at all. My loss-- I love her! I'm going to read more, definitely.
The 'Age of Innocence' is the 1870s in New York; it's a city on the brink of total change, but for this moment, a tiny group of wealthy New Yorkers cling to traditions and standards that dictate impeccable behavior in public, and determined ignorance of anything unpleasant. Newland Archer loves this society and lives by its rules unquestioningly, until he meets his fiancee's cousin Madame Olenska. Knowing her makes him wonder about everything he's ever believed.
It's a wonderful book, so beautifully written, and the story doesn't quite take the predictable path. Newland is in a prison of his own making, but he doesn't know it until it's almost too late.
Wharton published The Age of Innocence in 1920 and it won the 1921 Pulitzer Prize for literature. Therefore it counts as my 'prize-winner' selection for the Back to the Classics Challenge. She was the first woman to win a Pulitzer.