As Abraham Lincoln prepared to take the oath of office for a second time, on 4 March 1865, the nation waited to hear what he would say about its future. Triumphalism at military success? A call to further sacrifice? Vengeance on the rebel South or an outline for reconstruction?

'What it means to be an American': Abraham Lincoln and a nation divided Read more

It was to be none of these things, and thus Lincoln’s Second Inaugural is enshrined in the national memory.

Edward Achorn, a journalist and historian, considers Lincoln’s address and the dying flames of civil war in which it arose. He adds sketches of people such as the supreme court chief justice, Samuel Chase, (who thought he should have been inaugurated that day), abolitionist and orator Frederick Douglass, nurse Clara Barton and poet Walt Whitman, with his tart description of the capital city: “This huge mess of traitors, loafers, hospitals, axe-grinders, & incompetencies & officials that goes by the name of Washington.”

It is also, of historical necessity, the story in parallel of John Wilkes Booth’s obsession with Lincoln and involvement in a conspiracy to kidnap him on inauguration day or even to assassinate him there, perhaps in some imitation of the murder of Julius Caesar. Booth is the second character in the book.

In early March 1865, Washington was a mess. Literally with mud-soaked streets and crowded hospitals treating combatants; figuratively, with unscrupulous war profiteers and a dysfunctional Congress racing to the end of its session. In the war itself, William Tecumseh Sherman continued his march through the South while Ulysses S Grant tightened the noose around Lee at Petersburg.

In the midst of it all stood Lincoln. The French minister in Washington wrote that “[h]is face denotes an immense force of resistance and extreme melancholy. It is plain that this man has suffered deeply.” The president’s own secretary, John Hay, noted that “the boisterous laughter became less frequent year by year; the eye grew veiled by constant meditation on momentous subjects”.

Achorn wisely avoids deep psychobiography but simply and accurately notes that “Lincoln’s hard life had left him with thick scar tissue over his psychic wounds” from his upbringing, yet the war “had reawakened his thoughts about God’s role in this world of suffering”.

Lincoln’s religion or lack thereof has been a subject of lively debate. Achorn falls squarely in the pro-belief camp. Indeed, Lincoln had foreshadowed the themes and words of the Second Inaugural in remarks in 1862 to a delegation of Chicago ministers who wanted him to move more quickly on slavery. Achorn believes Lincoln spoke truthfully, not cynically, in saying to General Ethan Allen Hitchcock: “[D]id I not see the hand of God in the crisis – I could not sustain it.”

Facebook Twitter Pinterest A memorial edition of The National News, 14 April 1866. Photograph: Reuters

In his message to Congress in 1861 and more famously at Gettysburg, Lincoln put the vast struggle in a universal context affecting all humanity, asking if republics could survive. Particularly after the Emancipation Proclamation, the war had proceeded beyond the expectations of either side into a war not only for the Union but to abolish slavery, which Lincoln accurately described as “the cause of the war”.

Now, Lincoln went deeper, turning the inaugural address into an extended reflection on the causes of the war, divine justice and “the mystery of suffering”. As Achorn writes, Lincoln “would not bask in the glory of recent, hard-fought military victories, or present a detailed plan for reconstruction. He would speak about human depravity, about the hideous sin committed by both sides, and about the justice of God’s infallible, implacable, inescapable will.”

The speech was “a confession of grave national failure … Lincoln was freely stating that he had not been in control of the nation’s fate, a confession of weakness rare for any politician” – and, in a sense, that he was responsible for the calamity as well. While the evil of slavery had caused the war, both sides, not the South alone, were responsible for the conflict and its horrors. The sacrifice Lincoln now asked of all Americans was to sacrifice hatred and vengeance, and in their place put charity.

We treat the Second Inaugural as a valedictory, prior to Lincoln’s assassination a few weeks later. Douglass felt there was “murder in the air” that day, and he was right. As Lincoln walked through the crowd, the official planning the inauguration “happened to see a man jump” into the official procession, “determined to get close to Lincoln”. It was Booth (who had an official ticket; read the book to find out why), but after what one described as a “severe struggle” Booth was released – a great “what if” of history.

'Right makes might': Lincoln Project takes aim at Trump from Cooper Union Read more

The day was fraught with portents. Vice-President Andrew Johnson made a drunken speech to the Senate. Violent winds and rain gave way to bright sunshine as Lincoln rose to speak. Whitman noticed that “a curious little white cloud, the only one in that part of the sky, appeared like a hovering bird, right over him”. The many African Americans in attendance applauded vigorously but, as Douglass noted, during the speech the crowd was “wonderfully quiet, earnest, and solemn”.

Its broader reception was mixed, largely based on partisan affiliation, a reminder of how unpopular Lincoln was in certain parts of the North. Lincoln’s own verdict is typically direct: “It is a truth which I thought needed to be told; and as whatever of humiliation there is in it, falls most directly on myself; I thought others might afford for me to tell it.”

Achorn has done Lincoln justice, distilling the essence of the speech in a reflection Lincoln would have understood: “It was time for Americans to stop thinking about self-righteousness. The only way forward was to recognize that all had been wrong and to treat each other with mercy.”