Two extraordinary events occur in the mid-1840s. First, the United States Military Academy, at West Point, in a stroke of marvelous coincidence, graduates several classes of outstanding cadets, a group of young men who at the time are clearly superior to many of the classes that have preceded them. The second event is the Mexican War, the first time the armed forces of the United States takes a fight outside its own boundaries. The two events are connected, and thus, together, they are more significant than if they had occurred separately, because the events in Mexico served almost immediately as a brutal training ground for these cadets, who are now young officers.

They are a new breed of fighting man, the college-educated professional soldier, and the Mexican War is the first war to which West Point has given commanders. It is not a popular war, is seen by many opponents as nothing more than a land grab, the opportunity for the United States government to flex its muscles over a weaker enemy, and thus gain the spoils: South Texas, New Mexico, Arizona, California. What no one can know at the time is that the experience these young soldiers receive will have a profound effect on the battlefields of their own country in 1861. Not only do these men bring home the terrible visions of death and destruction, the experience that wars are not in fact great and glorious exhibitions, but they bring home something more -- the discovery that the old way of fighting a war, the Napoleonic School, is becoming dangerously outdated.

The discovery comes from the use of the latest improvements in technology, for the rifleman and the cannoneer, for the observer and the bridge builder. Mexico is very much a testing ground for the new killing machines: greater range, accuracy, and firepower. And so, these young officers are schooled not only in the skills of traditional command and tactics, but in the vastly improving knowledge of the art itself, of engineering and mathematics.

The effect that all of this will have thirteen years later, on the battlefields of our own country, cannot be underestimated. One of the many great tragedies of the Civil War is that it is a bridge through time. The old clumsy ways of fighting, nearly unchanged for centuries, marching troops in long straight lines, advancing slowly into the massed fire of the enemy, will now collide with the new efficient ways of killing, better rifles, much better cannon; and so never before -- and in American history, never since -- does a war produce so much horrifying destruction.

But this is not a story about the army, or about war, but about four men. Three of them serve their country in Mexico, two of them spend the decade of the 1850s in a peacetime army with very little constructive work to do. They are not friends, they do not share the same backgrounds. But their stories tell the stories of many others, weaving together to shape the most tragic event in our nation's history, and so their story is our story.

ROBERT EDWARD LEE

Born 1807, Lee graduates from West Point in 1829, second in his class, with the unequaled record of never having received a single demerit for conduct in his four years as a cadet. He returns home to Virginia to a dying mother and a scandal-laden family, and so resolves that his life shall bring atonement. Lee possesses an unwavering sense of dignity, and is thus often considered aloof, but his dedication to duty and his care for those around him reveal him to be a man of extraordinary compassion and conscience. His faith is unquestioning, and he believes that all of his accomplishments, all events around him, are the result of God's will.

Lee marries Mary Anne Randolph Custis and has seven children, but he is rarely home -- the sacrifice of being a career soldier. He distinguishes himself as a Captain of Engineers, goes to Mexico, and his reputation lands him on the staff of General in Chief Winfield Scott, the grand old man of the army. Lee performs with a dedication and a skill that makes heroes, and Scott promotes him twice, to Lieutenant Colonel. After the war he is named Commandant of West Point, finds it stifling, finds himself growing older with little prospect of advancement beyond his present rank, and he is not a man who will pull strings, or play politics for favors.

In 1855 the army forms the Second Regiment of Cavalry in Texas, and Lee astounds friends and family by volunteering for command. He sees this as his last opportunity to command real troops in the "real" army, and thus spends five years in the cavalry, which ultimately becomes another thankless and unsatisfying job. Serving under the harsh and disagreeable thumb of General David Twiggs, Lee asks for and is granted leave, after receiving word that his father-in-law, George Washington Parke Custis, the grandson of Martha Washington and the patriarch of his family's home, has suddenly died.

WINFIELD SCOTT HANCOCK

Born 1824 in Pennsylvania, one of twin boys, he graduates West Point in 1844. Hancock serves in Mexico with the Sixth Infantry, but only after waging war with his commanders to let him fight. He leads troops with some gallantry, but misses the army's great final victory at Chapultepec because he has the flu. He watches from a roof-top while his friends and fellow soldiers, Lewis Armistead, George Pickett, James Longstreet, and Ulysses "Sam" Grant, storm the walls of the old fort.

After the war, Hancock marries Almira Russell of St. Louis, considered in social circles, and by most bachelors there, to be the finest catch in St. Louis. She is beautiful and brilliant, and accepts her role as the wife of an army officer always with good grace and a superb ability to charm all who know her. They have two children, a son and a daughter.

Hancock, a large, handsome man, has the unfortunate talent of making himself indispensable in any assignment he is given, possessing an amazing talent for the drudgery of army rules and paperwork. This launches him into a dead-end career as a quartermaster, first in Kansas, then in Fort Myers, Florida, where the Everglades assaults the soldiers there with crushing heat and disease, snakes and insects, and the constant threat of attack from the Seminole Indians. He soon is transferred back to "Bloody Kansas," as the army tries to maintain control of rioting civilians confronting each other over the issue of slavery. Moving farther west with the army, he is named Quartermaster for Southern California and assumes a one-man post in the small but growing town of Los Angeles. But Hancock is never content to be a quartermaster, cannot forget his days in Mexico leading infantry, and aches for duty as a real soldier.

THOMAS JONATHAN JACKSON

Born 1824, Jackson arrives at West Point as a country bumpkin with homespun clothes and no prep school training, unlike the brilliant George McClellan or the aristocratic Ambrose Powell Hill, and has great difficulty at the Point. Jackson struggles with the studies, but has no vices, and so spends his time improving, and acquires a reputation as rigid and disciplined, and graduates in 1846 in the upper third of his class. All who know him there are certain that if the courses had gone a fifth year, Jackson would have reached the top.

In Mexico, as an artillery officer, he quickly shows his commanders he is not only suited for the heat of battle, but thrives on it. Jackson leads his two small guns into the fight with an intensity that puts fear into the enemy, and into many who serve with him. He is promoted three times, more than anyone in the army, and returns home a major.

After the war, Jackson grows weary of peacetime army life and applies for a position as an instructor at the Virginia Military Institute, in Lexington, Virginia. He is far from the most qualified candidate, but his war record and the fact that he is a native of western Virginia, and might assist in drawing recruits from that area, gain him the job. Thus he resigns from the army in 1851; he becomes a major in the Virginia Militia and embarks on a career in academics, for which, justifiably, he will never receive praise.

Jackson becomes a Presbyterian, and earns a reputation in local circles as a man of fiery religious conviction, if not a bit odd in his personal habits. He is seen walking through town with one hand held high in the air, thought by many to be constantly in prayer, and he is often sucking on lemons. He violates the law by establishing a Sunday school for slave children in Lexington, and justifies it by claiming it is the right of all of God's creatures to hear the Word.

In 1854 Jackson marries Eleanor Junkin, daughter of the president of Washington University, but a year later she dies in childbirth, as does the baby. Jackson's grief overwhelms him. He takes a long tour of Europe to recover emotionally, but his physical health, and his eyesight, give him constant trouble.

In 1857 he marries again, this time to Mary Anna Morrison, the daughter of a minister who is the founder of Davidson College in North Carolina. Their first child survives only a month. The tragedies of this time in his life place him more firmly than ever into the hands of his God, and he sees every aspect of his life, every act, as only a part of his duty to please God.

JOSHUA LAWRENCE CHAMBERLAIN

Born in 1828, Chamberlain graduates from Bowdoin College, Brunswick, Maine, in 1852. He is considered brilliant, with an amazing talent for mastering any subject. He enrolls in the Bangor Theological Seminary, considers the ministry as a career, but cannot make the final commitment, for though he often preaches Sunday services, he does not hear the calling. Chamberlain returns to Bowdoin as a teacher and is named to the prestigious Chair formerly held by Dr. Calvin Stowe. Chamberlain is now Professor of Natural and Revealed Religion, and speaks seven languages.

While part of Stowe's circle, Chamberlain becomes well acquainted with Stowe's wife, Harriet Beecher Stowe, who at that time is working on Uncle Tom's Cabin. The book has considerable influence on Chamberlain and causes him to see far beyond the borders of Maine, to the difficult social problems beginning to affect the country.

He falls desperately in love, and marries Frances "Fannie" Adams, daughter of a strict and inflexible minister. Fannie is a complex and difficult woman, burdened by her own family's awkward collapse -- her father marries a woman barely older than she is. Fannie is moody and seemingly hard to please, but Chamberlain loves her blindly. While his distinguished position and title satisfy her, he begins to slide into a long period of discontentment and to focus more on the gathering tide of conflict, the loud and bloody threats to his country.