How Did King of the Hill End on Fox?

The end of Fox's King of the Hill happened twice - first on the network itself and then in syndication. Which episode was the intended series finale?

King of the Hill [TV series] RARE promo advance soundtrack CD

King of the Hill Voices: Behind Favorite Characters

King of the Hill' might return to Fox

King of the Hill (season 11) - Wikipedia

Fox's 'King of the Hill' Was the Last Bipartisan TV Comedy - The Atlantic

Johnny Hardwick dead: 'King of the Hill' voice of Dale Gribble

King of the Hill Reboot Not Happening On Fox, I Tell You What - IGN The Fix: Entertainment - IGN

Why did 'King of the Hill' end? - Quora

Fox in 'Preliminary Conversations' to Revive 'King of the Hill