What season was it cancelled?

That was after season 2. In fact, they filmed that finale thinking the show wouldn't come back. And then it was renewed for 13 episodes, which is part of the reason why they didn't put C/S together to start season 3. They anticipated putting them together in episode 13 of season 3 and ending there. But then before they returned in season 3, they were extended for six more episodes. That's why season 3 looks like two separate seasons.

Season 4 had the same fate, except the show was renewed sooner and got its full renewal fairly early.

---
"I like a Major with hot lips & I'll tell you why!"
"Why?"
"Exactly."---M*A*S*H

Season 2. It was cancelled, then brought back for season 3 due to the campaign. Season 3 didn't return until that January though, for only 13, then an extra 6, which was why the season was shorter than seasons 2 and 4.

Season 2. Coincidentally, it's also the season the show *should* have been canceled. It was already an average season but man, oh man, did it go off the rails after that;

For every lie I unlearn I learn something new - Ani Difranco