Corrected entry: Political consultant Mandy Hampton disappeared completely with absolutely no explanation between the first and second seasons. She was in the last episode of the first season and not in the first episode of the second (which took place only a few minutes later) and no one ever explained where she went.
Corrected entry: There are occasional references throughout the show to the Bartlet family owning a farm in Manchester, NH. Manchester is the largest city in that state, and not in a rural area: saying they "have a farm in Manchester" would be like saying they "have a farm in Baltimore" (or Glasgow, for the UK readers among us). No one with roots in New Hampshire as deep as the fictional Pres. Bartlet's are supposed to be would ever be so inaccurate as to refer to the agricultural parts of the state as being Manchester.