The Story of the Kelly Gang, an Australian film, was the world's first feature-length film. IMDB has information on the cast, box office, and budget. It lasted more than an hour, and the reel length was approximately 4,000 feet. To put that into perspective, a small 5-inch reel of film can hold up to 200 feet, a 6-inch can hold 300 feet, and a 7-inch can hold 400 feet. Depending on the size of the reel, that's at least 10 reels of 7-inch film and up to 20 reels of 5-inch film.