Gregg Segal for TIME

A few weeks before Captain George S. James sent the first mortar round arcing through the predawn

darkness toward Fort Sumter, South Carolina, on April 12, 1861, Abraham Lincoln cast his Inaugural

Address as a last-ditch effort to win back the South. A single thorny issue divided the nation, he declared:

"One section of our country believes slavery is right and ought to be extended, while the other believes it

is wrong and ought not to be extended. This is the only substantial dispute."

It was not a controversial statement at the time. Indeed, Southern leaders were saying similar things

during those fateful days. But 150 years later, Americans have lost that clarity about the cause of the Civil

War, the most traumatic and transformational event in U.S. history, which left more than 625,000 dead —

more Americans killed than in both world wars combined.

Shortly before the Fort Sumter anniversary, Harris Interactive polled more than 2,500 adults across the

country, asking what the North and South were fighting about. A majority, including two-thirds of white

respondents in the 11 states that formed the Confederacy, answered that the South was mainly

motivated by "states' rights" rather than the future of slavery.

The question "What caused the Civil War?" returns 20 million Google hits and a wide array of arguments

on Internet comment boards and discussion threads. The Civil War was caused by Northern aggressors

invading an independent Southern nation. Or it was caused by high tariffs. Or it was caused by

blundering statesmen. Or it was caused by the clash of industrial and agrarian cultures. Or it was caused

by fanatics. Or it was caused by the Marxist class struggle.On and on, seemingly endless, sometimes contradictory — although not among mainstream historians,

who in the past generation have come to view the question much as Lincoln saw it. "Everything stemmed

from the slavery issue," says Princeton professor James McPherson, whose book Battle Cry of Freedom

is widely judged to be the authoritative one-volume history of the war. Another leading authority, David

Blight of Yale, laments, "No matter what we do or the overwhelming consensus among historians, out in

the public mind, there is still this need to deny that slavery was the cause of the war."

It's not simply a matter of denial. For most of the first century after the war, historians, novelists and

filmmakers worked like hypnotists to soothe the posttraumatic memories of survivors and their

descendants. Forgetting was the price of reconciliation, and Americans — those whose families were

never bought or sold, anyway — were happy to pay it.

But denial plays a part, especially in the South. After the war, former Confederates wondered how to hold

on to their due pride after a devastating defeat. They had fought long and courageously; that was beyond

question. So they reverse-engineered a cause worthy of those heroics. They also sensed, correctly, that

the end of slavery would confer a gloss of nobility, and bragging rights, on the North that it did not

deserve. As Lincoln suggested in his second Inaugural Address, the entire nation, North and South,

profited from slavery and then paid dearly for it.

The process of forgetting, and obscuring, was long and layered. Some of it was benign, but not all. It

began with self-justifying memoirs by defeated Confederate leaders and was picked up by war-weary

veterans on both sides who wanted to move on. In the devastated South, writers and historians kindled

comforting stories of noble cavaliers, brilliant generals and happy slaves, all faithful to a glorious lost

cause. In the prosperous North, where cities and factories began filling with freed slaves and their

descendants, large audiences were happy to embrace this idea of a time when racial issues were both

simple and distant.

History is not just about the past. It also reveals the present. And for generations of Americans after the

Civil War, the present did not have room for that radical idea laid bare by the conflict: that all people really

are created equal. That was a big bite to chew.

The once obvious truth of the Civil War does not imply that every soldier had slavery on his mind as he

marched and fought. Many Southerners fought and died in gray never having owned a slave and never

intending to own one. Thousands died in blue with no intention to set one free. But it was slavery that had

broken one nation in two and fated its people to fight over whether it would be put back together again.

The true story is not a tale of heroes on one side and villains on the other. Few true stories are. But it is a

clear and straightforward story, and so is the tale of how that story became so complicated.

Bleeding Kansas

History textbooks say the Civil War began with the shelling of Fort Sumter. The fact is, however, that the

Founding Fathers saw the whole thing coming. They walked away from the Constitutional Convention

fully aware that they had planted a time bomb; they hoped future leaders would find a way to defuse it

before it exploded. As the Constitution was being written, James Madison observed, "It seems now to be

pretty well understood that the real difference of interests lies not between the large and small but

between the Northern and Southern states. The institution of slavery and its consequences form the line."As long as the disagreement remained purely a matter of North and South, the danger seemed

manageable. But then North and South looked to the west. All that land, all those resources — the idea

that the frontier might be closed off to slavery was unacceptable to the South. It felt like an indictment and

an injustice rolled into one. Slave owners were not immune to the expansionary passion of 19th century

America. They too needed room to grow, and not just to plant more cotton. Slaves could grow hemp and

mine gold and build railroads and sew clothes. The economic engine of slavery was immensely powerful.

Slaves were the single largest financial asset in the United States of America, worth over $3.5 billion in

1860 dollars — more than the value of America's railroads, banks, factories or ships. Cotton was by far

the largest U.S. export. It enriched Wall Street banks and fueled New England textile mills. This

economic giant demanded a piece of the Western action.

In 1854, the Kansas-Nebraska Act proposed to let territorial settlers decide the future of slavery. Never in

U.S. history had so much depended on so few so far beyond the rule of law. There was a footrace to the

distant prairie, and Kansas, where the racers clashed, was where the war started, not Fort Sumter. And

everyone involved knew exactly what the killing was about.

It was on May 21, 1856, that a proslavery army, hauling artillery and commanded by U.S. Senator David

Rice Atchison of Missouri, laid waste to the antislavery bastion of Lawrence, Kans. "Boys, this is the

happiest day of my life," Atchison declared as his men prepared to teach "the damned abolitionists a

Southern lesson that they will remember until the day they die."

One of those abolitionists was John Brown, who tried to come to the aid of Lawrence but arrived too late.

Three days later, as Brown pondered what to do next, a messenger arrived with news from far-off

Washington: an antislavery leader, Senator Charles Sumner of Massachusetts, had been clubbed nearly

to death by South Carolina Congressman Preston Brooks while sitting at his desk in the Senate chamber

after delivering a fiery speech titled "The Crime Against Kansas." Brown went "crazy — crazy" at the

news, his son reported. That night he led a small group, including four of his sons, to a proslavery

settlement on Pottawatomie Creek. Announcing themselves as "the Northern army," Brown's band

rousted five men, led them into the darkness and hacked them to death with swords.

Two contending armies, artillery fire and flames, bloodshed in the Senate and corpses strewn over

dew-damp ground. People at the time knew exactly what to call it: civil war. Kansas Territorial Governor

Wilson Shannon used the phrase himself in a warning to President Franklin Pierce. "We are standing on

a volcano," Shannon added.

The reason for the eruption was simple. As Brown explained, "In Kansas, the question is never raised of

a man, Is he a Democrat? Is he a Republican? The questions there raised are, Is he a Free State man?

or Is he a proslavery man?" This is why armies marched and shells burst and swords flashed.

The Fracture

From there, the remaining steps to Fort Sumter seemed to follow inexorably. The Supreme Court, in its

infamous Dred Scott decision, tried to answer the question in favor of slave-holders. The backlash was

furious. In Kansas, settlers passed competing constitutions, one slave and one free, and the battle over

which one Congress should accept splintered the Democratic Party. When Stephen A. Douglas failed to

reunite the Democrats in 1860, he opened the door to a Lincoln victory.Meanwhile, Brown organized a quixotic plot to invade the South and stir up an army of slaves. Quickly

captured at the armory in Harpers Ferry, Va., tried for treason and hanged, he was hailed by abolitionists

as a martyr. After that, the idea that Northern Republicans supported slave rebellion became the defining

theme, for Southerners, of the 1860 election. A vote for Lincoln was in many minds a vote for the sort of

blood-soaked insurrection that had freed the slaves of Haiti and left thousands of white slave owners

dead.

Abolitionists had "inspired [slaves] with vague notions of freedom," explained President James Buchanan

as he prepared to leave office. "Many a matron throughout the South retires at night in dread of what may

befall herself and her children before morning," making "disunion... inevitable." As Southern states began

to declare their independence, they echoed this theme. South Carolina's leaders indicted the North for

encouraging "thousands of our slaves to leave their homes, and those who have remained have been

incited by emissaries, books and pictures to servile insurrection." Mississippi affirmed, "Our position is

thoroughly identified with the institution of slavery — the greatest material interest of the world," adding,

"There was no choice left us but submission to the mandates of abolition, or a dissolution of the Union."

Georgians declared, "We refuse to submit."

Even as the conflict turned to all-out war, many people still hoped for a way to put things back as they had

been. As George McClellan, General in Chief of the Union Army, wrote to a friend in 1861, "I am fighting

to preserve the integrity of the Union & the power of the [government] — on no other issue. To gain that

end, we cannot afford to raise up the negro question — it must be incidental and subsidiary." His words

go to the root of a persistent question: How could slavery be the cause of the war when so many in blue

had no interest in emancipation? McClellan was speaking for the millions whose goal was not to free the

slaves but to preserve the Union.

What McClellan did not perceive, though, was that the Union and slavery had become irreconcilable. The

proposition on which the revolutionaries of 1776 had staked their efforts — the fundamental equality of

individuals — was diametrically opposed by the constitution of the new Confederacy. "Our new

government is founded upon exactly the opposite idea; its foundations are laid, its cornerstone rests,

upon the great truth that the negro is not equal to the white man; that slavery, subordination to the

superior race, is his natural and normal condition," explained Confederate Vice President Alexander

Stephens. In other words, the warring sides had stripped their arguments to first principles, and those

principles could no longer be compromised.

Fogging Memory

The forgetting began with exhaustion. "From 1865" — the year the war ended — "until the 1880s, there

was a paucity of writings about the war that really sold," says Harvard historian John Stauffer. "Americans

weren't ready to deal with the reality of the war because of the carnage and the devastation." When an

appetite for the story began to return, readers embraced only certain kinds of memories. There was no

market for books of war photographs. Ulysses Grant's 1885 memoirs were a best-seller, but the Union

general gave almost no attention to the events leading up to Lincoln's call for troops, while his touching

account of the Confederate surrender at Appomattox strongly conveyed the idea that it was best to move

on. There was an avid audience for essays by military leaders in the magazine The Century, describing

their battles in minute detail but paying scant attention to the big picture. This "Battles and Leaders"

series spawned an endless literature that, some critics say, treats the terrible conflict as if it were America's original Super Bowl, Yankees vs. Rebs, complete with watercooler analysis of the play calling,

fumbles and Hail Marys.

The first publishing success to really engage the reasons for the war was a strange and rambling book by

Confederate President Jefferson Davis. Twenty years earlier, Davis had framed the choice to secede in

simple terms: "Will you consent to be robbed of your property" —meaning slaves — or will you "strike

bravely for liberty, property, honor and life?" But looking back, he preferred to say that the slavery issue

had been trumped up by "political demagogues" in the North "as a means to acquire power."

Davis' book, The Rise and Fall of the Confederate Government, became a polestar for the Lost Cause

school of Civil War history, which takes its name from an 1866 book by Richmond newspaper editor

Edward Pollard. Highly selective and deeply misleading, the story of the Lost Cause was immediately

popular in the South because it translated the Confederacy's defeat into a moral victory. It pictured

antebellum life as an idyll of genteel planters and their happy "servants" whose "instincts," in Davis'

words, "rendered them contented with their lot... Never was there happier dependence of labor and

capital on each other."

But then: "The tempter came, like the serpent of Eden, and decoyed them with the majic word of

'freedom.'" Though outgunned and outnumbered, the South fought heroically to defend itself from

aggressors whose factories up north were the true slave drivers. And though God-fearing warriors like

Robert E. Lee and Thomas "Stonewall" Jackson outgeneraled their foes at every turn, ultimately the

federal swarm was too large and too savage to repel.

The Lost Cause story required a massive case of amnesia. Before the war, Southerners would have

scoffed at the idea that the North was overwhelmingly stronger. They believed that King Cotton was the

dominant force on earth and that powerful Britain — where roughly 1 in 5 people depended on cotton for

a living — would intervene to ensure Confederate victory.

But people were eager to forget. And so Americans both Southern and Northern flocked to minstrel

shows and snapped up happy-slave stories by writers like Thomas Nelson Page and Joel Chandler

Harris. White society was not ready to deal with the humanity and needs of freed slaves, and these

entertainments assured them that there was no need to. Reconstruction was scorned as a fool's errand,

and Jim Crow laws were touted as sensible reforms to restore a harmonious land.

A Quarrel Forgotten

Instead of looking back, postwar Presidents stressed the future, adopting the reconciling tone of Grant at

Appomattox. William McKinley, assassinated in 1901, was the last Civil War veteran to lead the country.

His successor, Theodore Roosevelt, was the living embodiment of reconciliation and moving forward. His

father had served the Union cause; his plantation-raised mother had supported the South; his childhood

was a master tutorial in leaving certain things unsaid in the pursuit of harmony.

By the 50th anniversary of Gettysburg, it was nearly impossible to know from the commemoration why

the war had happened or who had won. The year was 1913, and the President was Woodrow Wilson, the

first Southerner to hold the office since 1850. Wilson had been a historian before entering politics, and his

book A History of the American People was tinged with Lost Cause interpretations. He described the Ku Klux Klan as "an empire of the South" created by men "roused by a mere instinct of self-preservation." It

was no surprise, then, that his remarks at Gettysburg completely avoided slavery. Instead he chose to

talk about "gallant men in blue and gray ... our battles long past, our quarrels forgotten."

So what was remembered? Two years after Wilson spoke at Gettysburg, partly influenced by Wilson's

book, filmmaker D.W. Griffith debuted The Birth of a Nation. It was the first film in history with a six-figure

production budget, yet by selling out theaters at the unheard-of price of $2 per ticket — nearly $44 in

current dollars — Griffith made a fortune. The movie brought the Lost Cause to cinematic life, with the

Klan saving the day in the final reel, rescuing white families from a group of marauding blacks. Then in

1939, a new Lost Cause melodrama made an even bigger impact: David O. Selznick's Gone with the

Wind. The story of plucky Scarlett O'Hara and the sad destruction of her "pretty world" of "Cavaliers and

Cotton Fields called the Old South" is the top-grossing film of all time, adjusted for inflation, according to

the website Box Office Mojo.

Both films begin in an antebellum South where all is peaceful and bright and trace the sad fall from

paradise into a hellish postwar world of carpetbagging Northerners and rapacious, incompetent freed

slaves. Such powerful cultural images were buttressed by the academic work of leading historians. At

Columbia University, William A. Dunning established himself as the leading authority on the postwar

South, and he brought up a generation of scholars with the belief that blacks were incapable of equality

and that Reconstruction was a disastrous injustice.

Equally influential was University of Illinois historian James G. Randall, who towered among Lincoln

scholars. Horrified by the senseless carnage of World War I, Randall saw it foreshadowed in the trenches

and torched fields of the Civil War. The chief villains, in Randall's orthodoxy, were Northern abolitionists

with their "reforming zeal."

Reigning over the study of slavery was Yale's U.B. Phillips, the son of slave owners. For decades he was

the only scholar to undertake a systematic examination of the plantation economy, which, he argued, was

a benign and civilizing force for African captives. He concluded that slavery was an unprofitable system

that would have soon died out peacefully. That would have surprised the Southerners who in the 1850s

certainly believed there was money to be made in slavery. In the decade before the war, per capita

wealth grew more than twice as fast in the South as it did in the North, and the prices of slaves and land

both rose by some 70%. If slavery was dying out, it sure was hard to tell.

Why It Matters

Historians began to break the grip of forgetfulness after World War II, as the civil rights movement

restarted the march toward equality. In 1941, Franklin Roosevelt ordered equal treatment for "workers in

defense industries or government." The next President, Harry Truman, desegregated the armed forces.

The next one, Dwight Eisenhower, dispatched federal troops to enforce school desegregation in

Arkansas. And so on, step by little step.

In 1947, the year Jackie Robinson broke baseball's color line, John Hope Franklin, a black historian then

at Howard University, published From Slavery to Freedom: A History of African Americans. This runaway

best seller revolutionized academic discussion of the black experience. The same year, Columbia's Allan Nevins published the first of eight volumes of Ordeal of the Union, which explored America's road to

disaster in great depth and clarity.

The Dunning School lost its grip on Reconstruction when C. Vann Woodward of Johns Hopkins published

The Strange Career of Jim Crow in 1955. The following year, Kenneth Stampp at Berkeley did the same

to U.B. Phillips with The Peculiar Institution, which examined the slave system through the eyes of the

slaves themselves for the first time.

With the centennial of the war approaching, a flood of outstanding Civil War history books hit shelves,

and the half-century since then has been rich in scholarship. Robust controversies rage and always will,

but the distortion and occluded memory that shaped the Lost Cause story is found now only on the

academic fringe. What energy exists in the modern version comes from a clique of libertarians who view

the Union cause as a fearsome example of authoritarian central government crushing individual dissent.

Slave owners make odd libertarian heroes, but by keeping the focus narrowly on Big Government, this

school uses the secession cause to dramatize issues of today. Outside academia, denial remains an

irresistible temptation for some politicians. Virginia Governor Bob McDonnell last year issued a 400-word

Confederate History Month proclamation without a single mention of slavery. "There were any number of

aspects to that conflict between the states," McDonnell later explained. "Obviously it involved slavery, it

involved other issues, but I focused on the ones that I thought were most significant for Virginia."

(Barraged by criticism, he corrected the omission.)

And in popular culture, as University of Virginia historian Gary Gallagher writes, "The Lost Cause's

Confederacy of gallant leaders and storied victories in defense of home ground retains enormous

vitality." It shows up in movies like Gods and Generals, in commemorative paintings, decorative plates

and battlefield re-enactments. By contrast, Gallagher searches in vain for a scene in any recent film that

"captures the abiding devotion to Union that animated soldiers and civilians in the North."

Why does this matter? Because the Civil War gave us, to an unmatched degree, the nation we became

— including all the good stuff. Had secession succeeded, it's unlikely that there could have been a stable,

tranquil coexistence between an independent North and South. Slaves would have continued running

away. The riches of the West would have been just as enticing. There never would have been the sort of

roisterous hodgepodge of wide-open energy that America became. One of the blessings of being able to

set up shop on a new continent was that Americans never had to be defined by clan or tribe or region.

We're the people who order a Coke from Atlanta and some New England clam chowder at a diner in Las

Vegas. The place where a boy from Mississippi goes to California to make a movie called Blue Hawaii.

Secession was about making more borders. At its best, Americanism is about tearing them down.

To be blind to the reason the war happened is to build a sort of border of the mind, walling off an

important truth. Slavery was not incidental to America's origins; it was central. There were slaves at

Jamestown. In the 1600s, writes Yale's David Brion Davis, a towering figure among historians, slave

labor was far more central to the making of New York than to the making of Virginia. As late as 1830,

there were 2,254 slaves in New Jersey. Connecticut did not abolish slavery until 1848, a scant eight

years before the fighting broke out in Kansas. Rhode Island dominated the American slave trade until it

was outlawed in 1808. The cotton trade made Wall Street a global financial force. Slaves built the White

House.Furthermore, if slavery had spread to the West, the country would have found itself increasingly isolated

in the world. Russia emancipated its serfs in 1861. The once sprawling slave system that had stretched

from Canada to South America was by 1808 still vital only in Brazil, Cuba and the U.S. The first nation

founded on the principle of liberty came dangerously close to being among the last slave economies on

earth.

Two fallacies prop up the wall of forgetfulness. The first is that slavery somehow wasn't really that

important — that it was a historical relic, unprofitable, dying out, or that all societies did it, or that the

slaves were happy. But slavery was important, and not just to the 4 million men, women and children

enslaved — a number equal to the population of Los Angeles today. And the fact that it ended is

important too.

The second fallacy is that this was only the South's problem and that the North solved it. Not long ago,

the New-York Historical Society mounted its largest-ever exhibition, titled "Slavery in New York." You can

still visit the website and listen to public reactions. Over and over again, visitors repeat the same theme:

as a teacher, as a college graduate, as a native New Yorker, "I knew absolutely nothing about this." As

long as that belief persists, spoken or unspoken, Americans whose hearts lie with Dixie will

understandably continue to defend their homes and honor against such Yankee arrogance.

Lincoln's words a few weeks before his death were often quoted after the war by those who wanted not

just to forgive but also to forget: "With malice toward none, with charity for all." But those words drew their

deepest power from the ones he spoke just before them: "Fondly do we hope, fervently do we pray, that

this mighty scourge of war may speedily pass away. Yet, if God wills that it continue until all the wealth

piled by the bondsman's 250 years of unrequited toil shall be sunk, and until every drop of blood drawn

with the lash shall be paid by another drawn with the sword, as was said 3,000 years ago, so still it must

be said 'the judgments of the Lord are true and righteous altogether.'"

In other words, the path to healing and mercy goes by way of honesty and humility. After 150 years, it's

time to finish the journey.