Originally, Touchstone Pictures had Kevin Costner top-billed over Robert Duvall, but Costner asked the studio to top-bill Duvall instead.
Kevin Costner really loved the "country's fillin' up" line. In the 1880s, the U.S. population had grown to over fifty million people.
The script doesn't specify where the story takes place, but Kevin Costner insisted on finding landscapes where "you couldn't see a fence, road, or another person."
As revealed during his appearance on The Arsenio Hall Show (2013), Sir Anthony Hopkins wrote fan letters to Kevin Costner and Robert Duvall after watching the movie, complimenting them both on their performances.