Robert Zemeckis had already established himself as a successful Hollywood director by the time he signed on to adapt the 1986 novel, Forrest Gump, by Winston Groom. Zemeckis always had a soft spot for wholesome, straightforward American storytelling, so his version of Groom's novel did not resemble its source material in tone at all, primarily because he chose to centralize the one-sided romance between Forrest and Jenny. In an article about how much the movie deviates from the book, Ryan Vlastelica writes for The AV Club, "Forrest’s mom is bitter and manipulative in the book; Sally Field plays her with boundless love and support. The book’s Lieutenant Dan is a thoughtful and philosophical man (who Gump doesn’t serve under, meaning he also doesn’t save Dan’s life), in sharp contrast to the Ron Kovic-esque figure played by Gary Sinise, who also feels more distinct for having an arc of finding peace. The film’s Jenny is a victim of abuse, which provides some texture to her wanderlust, bad relationships, and discontent (that the film creates this “motive” while judging her impulsiveness and the distance she keeps from Forrest is a mark against it). In the book the character is spacey and one-dimensional, sometimes on Forrest’s side, sometimes not, but never plausible as a lifelong romantic obsession."
Zemeckis takes some of the central ideas of the original novel and sentimentalizes them through a Hollywood lens. He wanted to create an inspiring story with a romantic tone rather than a caustic one. After Terry Gilliam and Barry Sonnenfeld both declined offers to adapt the novel, Zemeckis signed on, with filming beginning in August of 1993. Zemeckis devoted a great deal of energy to the special effects in the film, working with Ken Ralston and Industrial Light & Magic to merge contemporary shots with vintage historical footage, as well as compose impressive shots of Vietnam War recreations, the war rally at the Lincoln Memorial, and Gary Sinise's missing legs.
Zemeckis won an Academy Award for his direction of the film, and many critics praised his work on the film. Roger Ebert wrote, "The director, Robert Zemeckis, is experienced with the magic that special effects can do (his credits include the "Back To The Future" movies and "Who Framed Roger Rabbit"), and here he uses computerized visual legerdemain to place Gump in historic situations with actual people."
