This is the only entry in the series shot entirely in the US.
When Noah is interviewing Chris for a biography, he asks Chris about a clash that he participated in called The Battle of Adobe Walls, and Chris replies that it was a fight between 28 buffalo hunters and 600 Comanche Indians led by Quanah Parker, and among the white participants was William Barclay 'Bat' Masterson. The Battle of Adobe Walls was a real-life siege by approximately 700 Comanche, Kiowa and Cheyenne warriors of the small trading settlement of Adobe Walls, TX, on 6/7/1874, in which Masterson did indeed participate (this was the only time in the "Magnificent Seven" film series that a real-life gunfighter was mentioned). The siege lasted almost three days, and the Indians attacked the post several times but were driven back each time. The battle ended when one of the buffalo hunters, a man named Billy Dixon, used his long-range rifle and shot and killed a Cheyenne warrior sitting atop his horse at a distance of approximately 1500 yards; it so unnerved the Indians--whose medicine man had promised that they would be immune from bullets--that they turned around and left. Total casualties were four whites dead (one of whom accidentally shot himself in the head) and approximately 20 Indian warriors killed and at least that many wounded.
When Noah Forbes introduces himself to Chris, played by Lee Van Cleef, he likens himself to Ned Buntline. In For a Few Dollars More (1965), Van Cleef's character uses two long-barreled Colt revolvers whose model has come to be known as the "Buntline Special".
The last in the series of four "Magnificent Seven" movies.
Opened one day prior to The New Centurions (1972), both films feature character actors James Sikking and Ed Lauter.