James Stewart offered to play his own dead body in the Civil War story but was refused by John Ford who instead used a double who bore no resemblance to Stewart. When George Peppard imitates Stewart's voice during the grizzly bear reminiscence story he was reprimanded by Ford but yelled back that he wanted the audience to remember that Stewart played his father.
Stuntman Bob Morgan was seriously injured, and almost died, while performing a stunt in this picture. Toward the end of the film, there is a gunfight on a moving train between the sheriff and a gang of train robbers. Morgan was one of the stuntmen playing a robber and was crouched next to a pile of logs on a flatcar. The chains holding the logs together snapped, and Morgan was crushed by the falling logs. He was so badly hurt it took him five years to recover to the point where he was able to move by himself and walk unaided.
Due to the detail that would have been shown via the Cinerama process, the costumes had to be sewn by hand, rather than with a sewing machine, as they would have been during the time periods depicted in the movie.
Debbie Reynolds and George Peppard are the only cast members who appear in three of the five sequences in the film. According to Ms. Reynolds, in an interview for the documentary Cinerama Adventure (2002), her character of Lilith was originally supposed to have drowned in the river. However, it was decided that Lilith would best tie the generations of Prescotts together, so, she remained in the story to become an elderly lady in the film's conclusion.
John Ford's habit was to always sit beside the camera while it was filming so he could watch the action intently. Unfortunately because of the triple lens on the Cinerama camera, he kept appearing in shot until director of photography Joseph LaShelle hit on the idea of building a rig that allowed Ford to sit above the camera.
Some stock footage from other (non-Cinerama) epics were used. The Mexican army marching past the Alamo came from The Alamo (1960) and a Civil War battle was taken from Raintree County (1957). The final scenes of the modern U.S. were from This Is Cinerama (1952).
Because the 2 dividing lines that separate the 3 separate projections could not be totally edited into a seamless match, the directors skillfully used camouflage techniques to disguise the lines. Some of the objects used for this were trees, lamp posts, window edges, porch rails, building corners, doorways and wooden crates which were positioned at these points.
Since the three lenses of the Cinerama camera sat at angles to each other on the camera itself, it was very problematic for actors to film a scene as they would in front of a single-lensed camera. When their images were projected onto the three panels of the Cinerama screen, it would appear as though the actors were looking either slightly up-screen or slightly down-screen, and not directly at their fellow actors. This is very evident in a few scenes in the previous Cinerama film, The Wonderful World of the Brothers Grimm (1962). However, by the time this film went into production, this problem was solved somewhat. In order to compensate for the lens angles, actors would have to look one-third of the way in and toward the camera, and pretend that they were looking at their fellow actors. Hence, when their images were projected onto the Cinerama screen, it would appear as though they were looking at each other. It was a very difficult process for actors, which is one of the reasons that three-panel Cinerama was abandoned for narrative films after this film was released.
Hope Lange was cast as a love interest for George Peppard's character, but her scenes were cut from the final print of the film. She portrayed young Julie Stuart, the daughter of Henry Fonda's character, Jethro Stuart. After Lang's scenes were deleted from the film, Julie was later portrayed by Carolyn Jones.
During the Indian attack that was filmed in Lone Pine, California, a Conestoga Wagon tumbles down a hill. In order to create the illusion of the audience being inside of a tumbling wagon, a track was built down the slope of a small hill and the top portion of a Conestoga Wagon, without the wheels, was affixed onto a flatbed along with a mechanism that would turn the wagon over and over as the flatbed was guided down the hill. The Cinerama camera, in turn, was attached to one end of the flatbed so that it could shoot directly through the turning wagon as the stuntmen, including Loren Janes, were tumbled around the insides of the wagon along with boxes, barrels, blankets and other cargo. It took more than two days to prepare the scene and several takes to complete. In the final cut, this scene lasts no more than five seconds on the screen.
A comic book version of this film was published in conjunction with the film's release, as was the practice back then with all family and children's films. In the comic book, when Sheriff Ramsay (Lee J. Cobb) tries to prevent Zeb Rawlings (George Peppard) from going after the outlaw Gant (Eli Wallach), Rawlings whacks Ramsay over the head with his rifle and knocks him unconscious, which explains the bandage on Ramsay's forehead in the next scene. No such explanation is offered in the film; it is as if somebody had edited something out.
The second non-documentary Cinerama film, it was also one of the last to use the old three-camera technique, resulting in two very visible, somewhat distracting, dividing lines in the non-Cinerama print and all TV and home video versions.
This was one of only two films made in true Cinerama which were shown in regular theatres after their first runs. None of the previous Cinerama films were ever shown in regular theatres because they were travelogues and documentaries made only to show off the process, as opposed to telling a story, and it would have been pointless to show these in a "regular" format.
The train station in the film at "Gold City" was shot at Perkinsville, Arizona, and is still standing, although in a state of disrepair. It is now the mid stopping point of the Verde Canyon Scenic Railroad. The train station, the town sign and several other smaller buildings still exist.
Henry Hathaway was famous for his salty language. Debbie Reynolds instigated a swear jar on the set in an effort to curb him of his excesses - every time he swore, she would have to put some coins into the jar. Reynolds ended up losing quite a bit of money.
Cinerama was so expansive, it couldn't really be configured for close-ups. The nearest it could manage was to place a key actor in the central frame and try to get in as close as possible. This proved to be very intimidating for a lot of actors as the camera (an enormous piece of apparatus under a black hood with 3 lenses) would be literally in their face - 18 inches away, to be precise.
As part of their collaboration with Metro-Goldwyn-Mayer, Cinerama agreed to modify their system by reducing the frame rate to 24 frames per second (the industry standard) so that this film would have an exhibition life after its Cinerama engagements.
The film was inspired by a factual series on the settling of the West of the same name that had appeared in 'LIFE' magazine and which had been followed by a identically titled 2-LP set of western songs sung mostly by Bing Crosby and Rosemary Clooney. Many of the songs on the record album were also used in the film soundtrack, like "Bound for the Promised Land" and "What Was Your Name in the States?"
During his narration at the beginning of the film, Spencer Tracy refers to Native Americans as "primitive man". This statement is still on the DVD version, although it could be considered racist today.
A lot of the actors were very intimidated by the three-lens Cinerama camera and felt they had to elevate their performance to something approaching the way one performs on the theatrical stage as opposed to the more subtle style of acting normally required in front of a camera. This is why a lot of the actors in the film come across as being quite over-the-top.
No ordinary "single-camera" version was filmed simultaneously with the Cinerama version, resulting in two noticeable dividing lines on the non-Cinerama theater prints, video, TV and DVD versions (indicating the three synchronized film strips originally used). The same problem occurred with the other Cinerama film in release at the time, The Wonderful World of the Brothers Grimm (1962), which had not been shot in a "single-camera" version either. Both were MGM films.