Steven Spielberg said it was tough to persuade British actor Daniel Day-Lewis to play Abraham Lincoln - but the result was worth the struggle, winning rave reviews and Oscars speculation.
Lincoln is an intimate portrait of the 16th US president as he struggles to change history by abolishing slavery amid the still-raging Civil War.
For more than a decade, the veteran director had wanted to make a film about Lincoln, probably America's most revered president, who was assassinated in April 1865.
"I've just always had a personal fascination with the myth of Abraham Lincoln," he said ahead of the film's red-carpet premier at the American Film Institute (AFI) festival, which traditionally starts the annual Oscars race.
Spielberg lamented that Lincoln had been reduced to "a kind of cultural national stereotype," and no-one had made a film about him since 1939's Young Mr Lincoln by John Ford, in which Henry Fonda played the president.
The three-time Oscar-winning filmmaker decided from the start not to attempt to tell the Republican politician's whole life story, saying: "We would have been dilettantes as filmmakers and as actors."
With screenwriter and playwright Tony Kushner, who won a Pulitzer prize for the play Angels in America in 1993, Spielberg opted to focus on the final months of Lincoln's life and his battle to abolish slavery.
The result is an intimate film mostly shot in interiors, apart from an opening battle scene, where the drama is driven by dialogue and a stellar cast including Tommy Lee Jones, Sally Field and Joseph Gordon-Levitt.
Day-Lewis's performance has already got some talking about the possibility he could win a third best actor Oscar to go with his golden statuettes for 1989's My Left Foot and 2008's There Will Be Blood.
The actor, known for his pickiness in choosing roles, hesitated for a long time to portray a "life that has been mythologised to that extent".
"Least of all did I want to be responsible for irrevocably staining the reputation of the greatest president this country's ever known," he added.
Spielberg confirmed: "It was hard to get him to say yes. If he had finally and ultimately said no, I would never have made the movie Abraham Lincoln. It'd be gone."