CNN  — 

Embodying Jacqueline Kennedy’s darkest hours in the upcoming movie “Jackie” was no easy task for Natalie Portman.

“Jackie,” directed by Pablo Larraín, tells the story of the aftermath of President Kennedy’s assassination from his wife’s perspective.

“The way she handled herself in that sort of crucible was so strong and intelligent,” Portman told CNN. “It was really interesting to see that very private side – when you start looking into it – her crisis of faith, her doubts in God, her thoughts of suicide, but also her intense intelligence.”

Related Link: See Natalie Portman as Jackie Kennedy

Portman mastered the accent and mannerisms of the former first lady for the film.

“The accent is very specific. It’s nice because it kind of tells a story, too, about her background,” Portman said. “She has this very New York accent, [in] which you see this sort of Long Island heritage. Then you also get this kind of breathiness in the voice that shows this very desire to present yourself, especially when she was on TV it gets kind of breathier, to present yourself in a kind of feminine, coy way.”

In the film, Jackie is interviewed a week after Kennedy’s death by a reporter [played by Billy Crudup] for “Life” magazine. In the course of their conversation, she shaped the memory of her husband by quoting from the 1960 Broadway musical, “Camelot” – forever linking Kennedy’s unfinished term in office to “the brief shining moment” of Camelot.

“She really just was so smart,” Portman said. “[She] really understood history and really understood that the people who write history are the ones who define it. The story you write is more important than what actually happened, if you come up with a good enough tale.”

“Jackie” releases nationwide in theaters December 2.