Who was the director of the film whose success, along with that of An American Tail and The Land Before Time, prompted Steven Spielberg to establish his own animation studio?
An American Tail: An American Tail is a 1986 American animated musical adventure family comedy-drama film directed by Don Bluth and produced by Sullivan Bluth Studios and Amblin Entertainment. An American Tail:  The success of it, "The Land Before Time", and Disney's "Who Framed Roger Rabbit", as well as Bluth's departure from their partnership, prompted Steven Spielberg to establish his own animation studio, Amblimation. Who Framed Roger Rabbit: Who Framed Roger Rabbit is a 1988 American live-action/animated fantasy film directed by Robert Zemeckis, produced by Frank Marshall and Robert Watts, and written by Jeffrey Price and Peter S. Seaman.
Robert Zemeckis