Duck Swanson is the eldest son of Claire and Roger Swanson. Duck surprises and shocks Anita Sheehan the night of the Kennedys' party because he looks so much like her son who died in Vietnam. Duck is a very sensitive and intelligent young man. He is concerned that he has upset Anita without intending to do so. Duck earns a full scholarship to Yale, but instead marries Libby Fleming and drops out of school. It was well known that Duck and Libby intended to remain sexually inactive until they married. One night while babysitting Melissa Greene in the haunted house, the two have sex with each other before they even know what has happened. It is from this experience that Libby becomes pregnant.