The most famous and challenging beard of them all sits on the chin of Daniel Day-Lewis, who eases into a role of epic difficulty as if it were a coat he had been wearing for years. It is both a curiosity and a marvel of modern cinema that this son of an Anglo-Irish poet should have become our leading portrayer of archaic Americans. Hawkeye (in “Last of the Mohicans”), Bill the Butcher (“Gangs of New York”), Daniel Plainview (“There Will Be Blood”) — all are figures who live in the dim borderlands of memory and myth, but with his angular frame and craggy features, Mr. Day-Lewis turns them into flesh and blood.

Above all, he gives them voice. His Lincoln speaks in a reedy drawl that provides a notable counterpoint to the bombastic bellowing of some of his allies and adversaries. (John Williams’s score echoes this contrast by punctuating passages of orchestral grandeur with homey scraps of fiddle, banjo and parlor piano.)

The script, by Tony Kushner, is attentive to the idioms of the time without being too showy about it. Lincoln is eloquent in the manner of the self-taught provincial prodigy he was, his speech informed by voracious reading and also by the tall tales and dirty jokes he heard growing up in the frontier country of Kentucky and Illinois. He uses words like “shindee” and “flib-flub” and likes to regale (and exasperate) his cabinet with homespun parables, shaggy dog stories and bits of outhouse humor. His salty native wit is complemented by the clear and lofty lyricism that has come down to us in his great speeches.

The main business of “Lincoln” is framed by two of those, the Gettysburg Address — quoted back to the president by awed Union soldiers on a January night in 1865 — and his Second Inaugural Address, which he delivered a little more than a month before the end of the Civil War and his own assassination. These are big, famous words and momentous events, and the task Mr. Spielberg and Mr. Kushner have set themselves is to make this well-known story fresh and surprising. Mr. Day-Lewis, for his part, must convey both the human particularity and the greatness of a man who is among the most familiar and the most enigmatic of American leaders. We carry him around in our pockets every day, and yet we still argue and wonder about who he was.