The Sam Elliott character tells the immigrants they are fools for having oxen for their train rather than horses. The truth is that most pioneers used oxen rather than horses for pulling their wagons west, unlike the depiction in most westerns. Oxen are slower but better suited for such a trip because they are stronger, able to endure under duress, are less picky eaters, are more sure-footed, can better pull fully loaded wagons up mountains, are less easily spooked, and, upon arrival at a destination, would be better suited to farm life.
They mention the "White Elephant" bar when they're in Ft. Worth, which still exists today.
Many of the scenes set in Fort Worth, Texas, were actually filmed in the present-day Fort Worth Stockyards historic district.
Captain Shea Brennan and Sergeant Thomas both wear Pinkerton Detective Agency badges. Pinkerton is a private security guard and detective agency founded in 1850, it still exists to this day in the form of Pinkerton Security. In 1871 the US government contracted law enforcement in certain territories to Pinkerton as they did not have sufficient US Marshalls, Pinkerton agents were tasked with enforcing federal law in the territories and Indian Nation, they sometimes were also hired as private security for wagon trains heading west. As of 1883 Pinkerton was the largest private government contractor in the world, in the 1890's the government began using Pinkerton agents against organized labor groups, Pinkerton agents quickly became known as strike breakers and by the early 20th century were not well liked by the general public. Pinkerton agents would infiltrate unions and use threats and intimidation to break up strikes.
The significance of the year 1883: On March 1 of the year 1872, President Ulysses S. Grant signed the Yellowstone National Park Protection Act, and was passed by Congress in the winter of the same year, which officially cemented Yellowstone as the world's first national park. Eleven years later, in 1883, construction of the Northern Pacific Railroad (funded by primary investor and Philadelphia Financier Jay Cooke) reached the north boundary of Yellowstone National Park.