10 Classic TV Characters Who Weren't Added Until Later Seasons

The West Wing was presented with a pretty huge problem when Rob Lowe departed the show towards the end of the fourth season. If Aaron Sorkin's series had a main character, Sam Seaborn might have been it. After all, he's the first person we see in the pilot, and a whole lot of episodes revolve around him.

Earlier in the season, the show had introduced a new character named Will Bailey, and so when Sam left, Will was given a greater significance. In addition to a replacement for Rob Lowe, he's actually a replacement in the show's world too, taking over as Deputy White House Communications Director after Sam leaves.

At first, it seemed like Will might be like an attempt to just pretend Sam was still on the show, but he would eventually grow into his own and become pretty distinct from Rob Lowe's character. The conflict established between Josh and Will also becomes pretty interesting, a conflict between being idealistic and being practical that is one of the central themes of the series.

The West Wing actually has a number of other late introductions to great characters, with some other notable ones being Ainsley Hayes (Emily Procter), Annabeth Schott (Kristin Chenoweth) and Matt Santos (Jimmy Smits). For a series about the constantly changing world of politics, The West Wing did a great job always getting new faces in there.