"It’s hard, man. It was not a fun movie to make in the sense of jokey, jokey, everyone’s just on the set laughing and having a good time," the actor explained on "Good Morning America" today. "It deals with really heavy subject matter."
"But you know, we owed it to the people involved in the rebellion," he continued, "and we owed it to our own country’s history to be completely honest with it and sort of show the reality of what life was then."
Hammer did, however, come up with an interesting way to lighten the mood for the crew: a pig roast.
"Funny story. I actually bought a pig from one of the extras," he began. "This guy is supposed to bring a pig and he brings this hog and it’s enormous. I mean it’s almost as tall as I am. Nate [Parker] looks at it and goes, 'This makes me really nervous. If we let this thing off its leash, if it runs wild, we’re not going to be able to get this thing.' And also it’s bigger than pigs were back then."
After determining the pig wasn’t the right fit for the film, the movie extra who brought the animal was unsure what to do with him. So Hammer, 30, offered to buy him.
"The guy was like, 'Aw man, I don’t even really want this pig. I was just bringing it for this. Now I guess I gotta drive it all the way home now,'" Hammer recalled. "I was like, 'So would you sell it?' And he goes, 'How much?' And I go, 'I dunno. How much do you want for it?' And he goes, '$150 bucks.' And I was like, 'Dude, here’s $300 bucks. Thanks for the pig.' And we had it for a little bit and then I cooked it for the whole crew. We had a big barbecue."
In the film, Hammer plays Sam Turner, a slave owner with a torn conscience. He said the movie is an important one to see because "it introduces a lot of interesting things into the conversation of race and shows the beginning and origins of how race relations work in this country."
"A lot of things we don’t realize, whether it’s the origins of policing, which were just people going around catching runaway slaves. They were called paddy rollers," he explained. "Then that turned into patrollers and now it’s patrolmen. The origin of what we have now, you see it in this movie in a way that’s sort of emotionally raw and makes you deal with it."
"The Birth of a Nation" opens nationwide Friday.