In keeping with the film’s tone, the literal translation of the film’s Italian title. C’era Una Volta, Il west, is actually Once Upon a Time, There was the west.
At $250.000 the Flagstone set cost $50.000 more than Leones’s first Western, A Fistful of Dollars, while the $3millions budget of west was more than all Leone’s previous five films put together.
Robert Ryan was originally cast as the Sheriff of Flagstone only to be replaced by Keenan Wynn when he opted to make The Wild Bunch instead.
Gabriele Ferzetti, who plays the crippled railroad boss Morton, played James Bond’s father-in-law in Her Majesty’s Secret service.
Morton was originally going to be played by Enrico Maria Salerno, who had dubbed Clint Eastwood’s voice in the Italian version of the Dollars movies
Harmonica’s ill-fated brother in flashbacks is played by the film’s production manager, Claudio Mancini.
Writer Mickey Knox would not be the only blacklist victim to work on the film: Lionel Stander, best remembered as the butler Max in TV’s Hart to Hart, stared as the trading post owner only to see his scene cut from US prints.
Leone compiled 150 volumes of research material and photographs for the film, visiting Texas, Arizona and Utah and spending much time at the American Railway Archives researching the history of the building of America’s trans-continental railroads.
Leone bought samples of Utah and Arizona’s red earth to Spain so he could match the Monument Valley scenes with his Spanish locations in the Sierra Nevada Mountains.
Unsatisfied with the look of the local Spanish extras, Leone hired expatriate Americans, Britons and Scandinavians living in Almeria to populate the streets of Flagstone for $14 a day.
Once Upon a Time in the West has the longest title sequence in film history
Director Robert Zemeckis paid homage to Once Upon a Time in the West in Back to the Future III, recreating the famous shot craning over the Flagstone station to reveal the fledgling town of Hill Valley
Blues Brothers and An American Werewolf in London director John Landis was one of the stuntmen on the film.