What was DreamWorks' first animated film?

Toy Story, released on November 17, 1995, was Pixar's first feature length film. It was part of a three-picture deal with Disney, with Pixar handling creation and production and Disney handling marketing and distribution. However, it is not considered a Disney-Pixar film because the two companies did not merge until 2006 (releases after the merger are branded as Disney-Pixar). AnswerYou can read the full, long and winding story of Pixar from it's inception in 1979 here.

http://en.wikipedia.org/wiki/Pixar

Or I can save you the trouble. The actual first movie that you might think of is Toy Story which was a Disney/Pixar joint venture.