FilmRise has acquired exclusive worldwide distribution rights to the horse-jumping documentary “Harry & Snowman” and plans a theatrical release in September.

The story centers on Harry de Leyer and a broken-down Amish plow-horse named Snowman winning the triple crown of show jumping in 1958 at the National Horse Show at Madison Square Garden. De Leyer had purchased Snowman just two years earlier for $80 off a truck bound for the glue factory.

The story was the subject of Robert Montgomery’s 1962 book “Snowman,” which is being republished by Simon and Schuster Children’s Publishing, and of Elizabeth Letts’ “The Eighty-Dollar Champion: Snowman, the Horse That Inspired a Nation.” Letts’ book was optioned in 2014 by MGM.

Dubbed “The Cinderella Horse,” Snowman still holds the American record for the high jump. The film, in which the 86-year-old de Leyer provides a first-hand account, has played at 18 festivals across the U.S. and won 10 audience awards.

Producers are Ron Davis, Karin Reid Offield and Paul Blavin of Graceful Light Entertainment.

“We are delighted to announce our acquisition of this touching, exhilarating film that not only tells a remarkable true story but also sheds an important light on animal rescue,” said Danny Fisher, CEO of FilmRise. “We are confident that the film will prove a crowd-pleaser when it hits theaters this fall.”

Magnolia Entertainment had announced at the Berlin Film Festival in February that it had bought the North American rights to “Harry and Snowman,” but that deal was not completed.

The FilmRise deal does not include rights to Australia and New Zealand. The deal was negotiated between Fisher and FilmRise’s VP of acquisitions Max Einhorn with James Andrew Felts of Concourse Media.