The Sioux nation was so pleased with the depiction of Native Americans in this movie, that they made Writer and Director John Milius an honorary tribe member.
Besides being a feared and well-respected lawman, Bucky O'Neill had also been an Indian scout and the Mayor of Prescott, Arizona, as well as a self-educated, very well-read and multi-lingual man (speaking French, Spanish, and several Indian languages). He and Roosevelt became fast friends and spent much of their time in the campaign discussing military history, Indian customs, and classic European literature.
Real casualties of the Rough Riders was forty percent, and many died from malaria, after the battle, because the U.S. would not let them back into the country, finally Theodore Roosevelt was able to get them back to Montauk, New York in a quarantine camp. On the Library of Congress American Memory website, there are early Edison movies of them at the Montauk quarantine camp.
The battles scenes were written from diaries and military dispatches, Theodore Roosevelt really did fall down from tripping over his sword.
Brian Keith's last movie. He played his part, as the President in this movie, a few weeks before his death. In an earlier John Milius movie, The Wind and the Lion (1975), Keith played Teddy Roosevelt, who was President during the time period of that movie.