Kevin Costner's ambitious Western film *Horizon: An American Saga – Chapter 1* has become one of the most-streamed titles on Prime Video in the US following its arrival on the platform. The development matters because the film flopped badly on its 2024 cinema release, and strong streaming performance is seen as essential to securing the release of the franchise's remaining planned chapters.

Costner devoted years to getting *Horizon*, a sprawling saga of early America, made, and the project was reportedly a source of tension around his exit from the hit series *Yellowstone*, in which he played patriarch John Dutton before the character was killed off. Conceived as four parts, *Horizon* debuted to mixed reviews — the first instalment holds a 51% critic score on Rotten Tomatoes — and failed to recoup its budget at the box office. The second part was delayed to allow the franchise to build a following on streaming, and after earlier runs on HBO Max and Netflix, Chapter 1 has now gained traction on Prime Video.