TLC has commissioned the two-hour film Letters To Jackie: Remembering President Kennedy, co-produced by Oscar-winning documentary filmmaker Bill Couturié’s The Couturie Co. and Steven Spielberg’s Amblin Television.

Based on the book Letters To Jackie: Condolences from a Grieving Nation by Ellen Fitzpatrick, the film revisits the months following Kennedy’s assassination, when more than 800,000 U.S. citizens and mourners around the world reached out to the First Lady in support. Letters To Jackie spotlights the strength and unity that emerged during one of the most difficult times in American history.

It will premiere in the fall to mark the 50th anniversary of the President’s death. Bringing the letters to life are 20 celebrities including Bérénice Bejo, Demián Bichir, Jessica Chastain, Chris Cooper, Viola Davis, Zooey Deschanel, Kirsten Dunst, Anne Hathaway, Allison Janney, John Krasinski, Melissa Leo, Laura Linney, Frances McDormand, Chloë Grace Moretz, Mark Ruffalo, Octavia Spencer, Hailee Steinfeld, Channing Tatum, Betty White and Michelle Williams.

Letters To Jackie is written and directed by Bill Couturié and produced by Anne Sandkuhler and Couturié. Darryl Frank and Justin Falvey exec produce.