The film is about how the community of Huntington, W.Va., struggled to cope after a 1970 plane crash killed most of Marshall University's football team and coaching staff, as well as numerous prominent Huntington citizens.
McConaughey plays Jack Lengyel, the coach who rebuilt the team -- and the community's hopes -- along with Red Dawson, a Marshall assistant coach who didn't get on the plane.
McConaughey said that after some initial trepidation about opening up to outsiders, the people of Huntington came to trust the filmmakers and have been extremely supportive of the movie.
Dawson even recently started going back to football games, he said.
"Being a part of making the movie was a somewhat very cathartic event for that guy and a lot of other people that were there in that town," McConaughey said.
"They're going back (to games) and not moving on, forgetting, but moving on, going: 'OK, this is a part of our life; it's who we are. ... I understand that and thanks for bringing it up. Thanks for doing it truthfully.' So, that feels really good. This is the most gratifying working experience I've ever had."