Mandy Hampton's (Moira Kelly) sudden disappearance from the West Wing between seasons one and two is one of the best remembered in TV history. Her position wasn't the only one that was unclear during season one; It seems that someone lost the white board notes that kept West Wing's politcal players straight in the first season because there are inconsistencies from one episode to the next, and never were any they explained.
In one episode, the Attorney General is said to be black, but later in the same season, he is played by a white actor. The Secretary of Agriculture is played by two different actors between episodes eight and 12. Congressman Wyatt (Kathleen York) is introduced in season one as a longstanding member with significant political sway, but just several episodes before she was left off of a vital Congressional role call. Above is a picture of the attorney general. As you can see, he is very white.