Reeve's three children, Alexandra Reeve, Matthew Reeve, and Will Reeve, an ABC News correspondent, told "Good Morning America" on Wednesday at the premiere that the film is a tribute to their father's legacy and the lasting impact he had on who they are today.

Christopher Reeve's children Alexandra, Matthew and Will were a united front at the New York premiere of the documentary honoring their late father. See all the red carpet photos

Very few actors embodied the role of a superhero quite like Christopher Reeve. For generations of movie-loving audience members, Reeve was – and is – Superman. He first stepped into the iconic DC role in 1978’s aptly titled Superman,