A film that documents the case to overturn Proposition 8, California's ban on gay marriage, on Saturday was among the winners at the 2014 Sundance Film Festival.

Filmmakers Ben Cotner and Ryan White won the Directing Prize for U.S. Documentary for The Case Against 8.

California voters approved Proposition 8 in 2008, sparking massive protests in California and Utah, home to the Mormon Church which played a key role in its passage.

The following year, two plaintiff couples – Kristin Perry and Sandy Stier and Paul Katami and Jeff Zarillo – challenged the amendment's constitutionally. It was the first case to aim for the Supreme Court.

In accepting their prize, Cotner and White thanked the plaintiffs, who have since married.

“[W]e hope all LGBT Americans can soon walk in the same footsteps you did,” White said.

The case's lawyers also attracted much media attention. David Boies and Ted Olson, who had previously played adversaries in the landmark Bush vs. Gore, came together to argue against Proposition 8. In the early stages of the case, Olson, the conservative of the pair, was accused of attempting to sabotage the marriage movement with a Supreme Court defeat.

The Case Against 8 will be broadcast on HBO later this year.