Tracy Lord is the elder daughter of a wealthy Philadelphia Main Line socialite family. She was married to C.K. Dexter Haven, a yacht designer and member of her social set, but divorced him two years ago, because he did not measure up to the exacting standards she sets for all her friends and family: He drank too much for her taste, and as she became critical of him, he drank more. Now, she is about to marry ''nouveau riche'' "man of the people" George Kittredge.