A few factoids:
* Director (and head of the department) Woolfgang Reitherman was interested in the book on which the movie is based because he had owned a pet fox..
* Development on the picture was started while The Rescuers was in production. There was a rough outline and sequences written, but no overall script.
* Ken Anderson, who had been a designer, board artist and character developer on a long string of Disney pictures, disliked working with Reitherman. (Story veteran Vance Gerry heard Ken shouting "Woolie's my enemy!" to production manager Don Duckwall on the phone.) So Woolie was relying on artist Mel Shaw (who did design work and the title sequence on The Rescuers) for a lot of F and H's early development.
* Ollie Johnston and Frank Thomas did a lot of test animation on the feature. Most of Frank's animation with Tod (the young Fox) and Copper (the hound dog) ended up in the film. A lot of Ollie's animation with the old hunting do Chief ended up on the cutting room floor.
* F and H was the feature in production when directing animator Don Bluth ankled the studio, taking a third of the animation staff with him. Don was working on scenes with the Widow Tweed when he left to start work on The Secret of NIMH. Because of Don's exit, the release of the feature was set back by a year.
* During production, directing animator Ron Clements moved into the story department. A few years later, he became a director on The Great Mouse Detective. In 1985, Ron pitched Hans Christian Anderson's The Little Mermaid at the first animation pitch section held by Jeffrey Katzenberg and Michael Eisner in the commissary conference room. Initially rejected, Ron wrote a treatment which Katzenberg liked, and The Little Mermaid was greenlit for development.
* The Fox and the Hound was the last picture on which Ollie Johnston and Frank Thomas animated, and the last feature on which department head Woolie Reitherman directed.
* The Fox and the Hound was the first feature on which Glen Keane both storyboarded and animated.
* The Fox and the Hound was the highest-grossing Disney animated feature to 1981. (We're talking dollars unadjusted for inflation.)