Kevin Costner’s passion project is nearly here.

Warner Bros. Pictures unveiledthe first trailerfor hisHorizon: An American Sagaon Monday. The epic — which star Costner, 69, also directed and co-wrote — spans two films that will both hit theaters this summer.

Per a synopsis,Horizon"explores the lure of the Old West and how it was won — and lost — through the blood, sweat and tears of many."

“Spanning the four years of theCivil War, from 1861 to 1865, Costner’s ambitious cinematic adventure will take audiences on an emotional journey across a country at war with itself, experienced through the lens of families, friends and foes all attempting to discover what it truly means to be the United States of America,” the synopsis adds.

In a special virtual event and moderated discussion on Friday surrounding the trailer, Costner said of the film’s title, “When you realize the country’s bigger and farther than anyone ever dreamed, it is about the horizon, because everybody is looking for something even today in the relationships and what’s going on at work, they’re looking for room, they’re looking for fresh air. And our 200-year march across this country was no different.”

Never miss a story — sign up forPEOPLE’s free daily newsletterto stay up-to-date on the best of what PEOPLE has to offer, from celebrity news to compelling human-interest stories.

Kevin Costner inHorizon: An American Saga(2024).Warner Bros. Pictures/YouTube

Horizon: An American Saga

Warner Bros. Pictures/YouTube

For Costner, one of his goals withHorizonwas “to project what really happened” during that specific time in American history.

“There was a great injustice incurred in the West, but it doesn’t minimize the courage it took for my ancestors to actually cut loose and go there,” the actor and filmmaker said. “And I recognize the resourcefulness it took, the bravery it took, to leave and make this march across this country.”

Costner added of the trailer specifically, “What I hope is that this is something that stays with [audiences] forever when they see the movie, and trying to find the moments in a trailer in 3 minutes to try to give people a feel where I might be taking them.”

Horizon’s cast also includesSienna Miller,Sam Worthington,Jena Malone, Abbey Lee,Michael Rooker, Danny Huston,Luke Wilson,Isabelle Fuhrman,Jeff Fahey,Will Patton, Tatanka Means, Owen Crow Shoe, Ella Hunt andJamie Campbell Bower.

Sienna Miller and Michael Rooker in Kevin Costner’sHorizon: An American Saga(2024).Warner Bros.

Sienna Miller and Michael Rooker in Horizon

Warner Bros.

In May 2023, Costner shared in an Instagram post that hehasn’t “felt this way about a moviesince we were makingDances with Wolves,” referencing hisOscar-winning 1990 epic.

“I’ve mortgaged 10 acres on the water in Santa Barbara where I was going to build my last house,” he said. “But I did it without a thought. It has thrown my accountant into a f—ing conniption fit. But it’s my life, and I believe in the idea and the story.”

Poster for Kevin Costner’sHorizon: An American Saga(2024).Warner Bros. Pictures

HORIZON: AN AMERICAN SAGA: CHAPTER 1

Warner Bros. Pictures

“At the end of the day I’m a storyteller, and I went ahead and put my own money into it,” he added to the outlet. “I’m not a very good businessman, so scratch your head if you will. I don’t know why, but I have not let go of this one.”

Costner told PEOPLE in November 2022 that hisson Hayes will also appear in the movie. At the time, the father of seven quipped thatHorizon’s “screenplay [has] been around longer than” 15-year-old Hayes' entire life.

He also said in the same conversation that the filmis “incredibly meaningful to me” and “the hardest thing I’ve ever done, but it’s exactly what I want to do.”

source: people.com