Steven Spielberg, Historian - NYTimes.com Having worked before at the intersection of Hollywood and history, helping a tiny bit with a respectable movie about the Cuban missile crisis called "Thirteen Days," I approached the new movie "Lincoln" with measured expectations. I had seen how a film could immerse viewers in onscreen time travel without messing up the history too much. But that was the most I hoped for. "Lincoln," however, accomplishes a far more challenging objective: its speculations actually advance the way historians will consider this subject. The movie, directed by Steven Spielberg and starring Daniel Day-Lewis as the 16th president, makes two especially interesting historical arguments. The first is to explain why the passage of the 13th Amendment, which abolished slavery, was overwhelmingly important to Lincoln in January 1865. The issue is not why passage was important; the movie explains that clearly enough. Instead, the problem is to explain the frenzied work to pass it in that month. As the historian Michael Vorenberg has observed, "No piece of legislation during Lincoln's presidency received more of his attention." Why the all-out effort in January, in a lame-duck session before a newly empowered pro-Lincoln Congress began? If Lincoln had waited until March, he could have called a special session of the new Congress, confident of having enough votes for House passage. The question has long vexed historians. The movie's answer is that Lincoln and his right-hand man in this work, Secretary of State William H. Seward, realized that the war might end at any time and that, when it did, any prospect for passing the amendment as a means to win the war would end with it. This is an intriguing argument. But the book the movie cites as its main evidentiary source, Doris Kearns Goodwin's "Team of Rivals," does not make it. Like other standard accounts, like James McPherson's renowned overview of the war, "Battle Cry of Freedom," Ms. Goodwin repeats Lincoln's own explanation, that he wanted prompt action because bipartisan approval would show national unity. But that's a dubious claim: the nation already was united, as it had proved in the November 1864 elections. The filmmakers' argument seems more convincing. Moreover, their reading of this part of Lincoln's political strategy provides the linchpin for another interpretive jump made in the film. In "Lincoln," the story of the battle to pass the 13th Amendment is deeply intertwined with a parallel story, unfolding at the same time, of secret negotiations to end the war. With Lincoln's consent and a note of safe passage, an influential conservative Republican, Preston Blair, went through the lines to the Confederate capital at Richmond, Va. Blair, on his own initiative, persuaded the Confederate president, Jefferson Davis, to send commissioners, including his vice president, back through the Union lines to discuss possible peace terms. The movie argues that at least one of Lincoln's motives in this episode was to secure votes for the 13th Amendment from Blair's conservative allies in Congress. The movie goes on to argue that Lincoln calibrated the timing of this diplomacy, including delaying his own meeting with the Confederate envoys, to be sure that nothing from it would materialize in time to jeopardize passage of the amendment. Lincoln met with the envoys three days after the amendment had passed the Congress. The peace initiative came to nothing. Historians have never been very clear on just why Lincoln entertained Blair's project in the way he did. But there is, in fact, good evidence to support the filmmakers' supposition of a deal linking the Blair peace initiative to the politics of the 13th Amendment. Seward later acknowledged that a principal ally in the vote, perhaps the most important one, was a Democratic congressman from Ohio named Samuel Cox, known as Sunset. Cox was a lame duck; he had just been defeated in the 1864 election. Cox later returned to Congress, this time representing a New York district. In an 1872 debate on the floor of the House, Cox was pushed hard by Henry Dawes, a Republican from Massachusetts, about Cox's past record on race matters, including Cox's 1865 vote against the 13th Amendment. According to The Congressional Globe, Cox replied: Mr. Seward, in an address at Auburn, said that I was one of the Democratic party who carried the thirteenth amendment. It required two thirds. I did not vote for it. I promised Mr. Lincoln (and his partner, Mr. Stewart, from the Springfield district, Illinois, then a member of the Committee on Foreign Affairs, who was with me at the time of the interview) that I would vote for that amendment if the President would undertake to send somebody down to Richmond and endeavor to secure an agreement on the part of the leaders of the confederacy to come back on the basis of the Constitution and the Union. I did this, so help me God, to stop the shedding of human blood. Mr. Lincoln sent down, as will be remembered, Mr. Blair. I intended to vote for the thirteenth amendment till I was advised that the condition failed. The vote was about coming off, when Mr. Ashley, of Ohio, who had charge of the bill, sent me word that there was an arrangement pending; that Messrs. Stephens, Hunter, and, I think, Judge Campbell, had arrived at General Grant's headquarters. A treaty was in progress. Hearing this, I said, 'Now I cannot vote for this amendment, because there is an agreement going on, and I prefer that the vote be postponed for the present. If the matter is pushed now I must vote against the amendment. I voted in the interest of human life, but, as the sequel showed, I did not forget human liberty. Mr. Chairman, I did so want to stop the shedding of blood. After vindicating in debate our right to amend the Constitution (antagonizing Mr. Pendleton and agreeing with Mr. Dawes and others) according to the prescribed mode, I said in debate that slavery had already been killed by the Army; that it was riddled with bullets, and might as well be buried. Was that the reason the gentleman voted against the measure? Dawes asked. "I had persuaded certain gentlemen to vote for that bill - enough of them to carry it," Cox replied, But I could not vote for it myself under the circumstances. That is the whole of the story. The gentleman knows that I speak veraciously. A fund of some seventy-five thousand dollars was raised, it was said, to buy up votes for that measure; and I understood that $10,000 was put up for my vote. Happily I escaped any reproach, for I did not vote for it, but against it. This account is mighty close to the narrative portrayed in the film. Incidentally, it appears that Ashley may have given his fellow congressman from Ohio some inside information about the status of the commissioners beyond what the House heard from President Lincoln. True, the movie takes some liberties for dramatic effect, particularly on the specific timing of the 13th Amendment vote and Lincoln's efforts to delay the commissioners' trip to Washington. It also has a caption implying that the vote occurred on Jan. 27 instead of on Jan. 31. The moviemakers rearranged, for example, the timing of a message from Gen. Ulysses S. Grant urging Lincoln to meet with the commissioners. Grant did send the message and Lincoln did go promptly to see the commissioners - "induced," he wrote, by Grant's request. But that exchange happened after the 13th Amendment vote. Yet the filmmakers have held to some essential truth even in these particulars. The commissioners first sought to cross the Union lines for their meeting on Jan. 29. Their arrival was no surprise; Lincoln had just talked about the situation with Blair. They were held in place at Lincoln's direction until he could ascertain their readiness to consider reunion "in a single common country" as a condition of negotiation. On the day of the amendment vote, the commissioners were still parked out of the way, at Grant's headquarters in Virginia. Then, on Jan. 31, at the climax of the amendment debate, Lincoln answered an urgent question from the House about whether the Confederate commissioners had come to see him. He answered, correctly and literally, that as far as he knew no such commissioners had come to the capital city. The amendment passed later that day, just as Lincoln completed his instructions for what Seward should say to the commissioners in advance of Lincoln's own journey to meet them. The basic facts surrounding the Blair initiative and the amendment vote are well established. But the movie's argument, connecting these two storylines, is not. Again, it does not appear in Ms. Goodwin's book. Nor does it receive much notice even in other standard accounts, like that of Mr. Vorenberg (though David Donald alluded to the possibility briefly in his Lincoln biography, as did Eric Foner in his book "The Fiery Trial: Abraham Lincoln and American Slavery"). Yet here again it turns out that the filmmakers have made a persuasive case, and in a way that written history usually fails to pursue, let alone accomplish. Historians, driven by a focus and a thesis, rarely recognize that their chosen issue has to be seen in the context of all the other issues in play at the same time. But this is exactly what presidents do. And to their credit, this is also what these filmmakers have done in re-enacting a president's world. According to the movie's production notes, Mr. Spielberg and the screenwriter, Tony Kushner, did significant research into this particular period, consulting various historians, including Ms. Goodwin. It appears that, puzzling over the coincidences and conjunctures, they developed their own original and plausible interpretation of what happened, peppering the script with lines drawn from documents and memoirs. Their interpretation is of an idealistic yet very practical president, but not an unethical one. Even the disingenuous note to the House about the Confederate commissioners embodied an element of real truth. After all, Lincoln was still not sure the commissioners had accepted the premise for a productive negotiation: readiness to discuss terms for rejoining the Union. So if, instead of his blandly deflating reply, he had given a different answer to the House question, he might have done too much to inflate the distracting balloon while the House vote was still in doubt. Because filmmakers can often devote far more resources to research than scholars can, because the sheer process of a painstaking reconstruction of a past world can itself yield insights about it, it has always been possible that filmmakers might add to our collective historical understanding, rather than either popularizing or debasing it. In Mr. Spielberg's "Lincoln," that possibility is happily realized. Philip Zelikow is a professor of history and an associate dean for the Graduate School of Arts and Sciences at the University of Virginia.