A turning point in the Civil War

July will bring the 140th anniversary of the battle of Gettysburg. Across Pennsylvania fields baking under the hot summer sun, reenactors will be out in force - most from the South, eager to replay, or imaginatively reverse, the whole encounter.

Reenactments began in 1913, a time closer to the battle than to us. But Gettysburg is a place that history embalmed as a special shrine long ago. What new could there be to say about it?

In the hands of two master historians, Stephen Sears and James McPherson, plenty, it turns out - though their books serve quite different purposes. McPherson's "Hallowed Ground" focuses on the battlefield today. Sears, whose "Gettysburg" will be published later this month, focuses on the battle, providing the best single-volume study in 30 years of what happened at Gettysburg from July 1 to 3, 1863.

"Hallowed Ground" is part of a series by Crown in which famous writers guide readers across their favorite landscapes. McPherson, author of the Pulitzer Prize-winning "Battle Cry of Freedom," fulfills the task with a crisp but informative tour of key spots at the Gettysburg National Military Park. Using appropriate monuments as "stops," McPherson provides apt, moving commentary about personalities, controversies, and oddities connected with the battle. Among the last, he says, a body was found as late as 1997 with the skull shattered, just one of close to 8,000 fatal wounds suffered during the battle.

Sears and McPherson agree on a major point of controversy: The Southern strategy of attack, not defense, was commander Robert E. Lee's decision; the failure of several days of attacks was Lee's fault. In their view, that does not decrease his stature as the greatest general in American history. But both authors also explain that his greatness was his undoing: Lee began to believe in his army's invincibility.

Both writers put the illusion in context. Two months earlier, Lee had staged daring, high-risk attacks at Chancellorsville, which made him think his men could work miracles.

Sears quotes liberally from the diaries of many soldiers and the accounts of the foreign observers around Lee. (The Union had none; its only friend was Russia, which later sent naval squadrons as token support.) The English colonel, Arthur Fremantle, summed up the emotional situation best in noting that all the Confederates held their enemy in complete contempt.

Sears shows nothing was wrong with the Union army that a competent general couldn't cure. But it had been plagued with overzealous or overcautious commanders. A week before the battle, Lincoln found in George Meade someone who could keep his balance. Meade was sharp enough to find high ground and lash himself to it. For technological reasons, defense normally won Civil War battles, and Gettysburg was the ultimate proof. Sears also shows how the Federals benefited from dogged work by their officers and from stealing pages from the Confederate book, especially by doing the unexpected.

Both historians mention many heroes, but none compares to the superbly named Union Col. Strong Vincent and his subordinate Joshua Chamberlain, a Bowdoin professor who, when his 20th Maine regiment ran out of ammunition, naturally decided to charge. Chamberlain is now famous from the PBS series "The Civil War" and the Ted Turner film "Gettysburg." But Sears's full discussion makes you wonder if the US would still exist intact without Vincent, who died of his wounds soon after the battle.

Both Sears and McPherson bring to light unknown aspects of the Gettysburg campaign, chiefly involving the role of blacks. Black troops were not yet fighting for the Union, but a black farmer named Bryan owned acreage right in the center of the Union line. He judiciously departed before the fight, but got $48 in damages from the government afterward.

Indeed, free black men (many lived in southern Pennsylvania, near the Mason-Dixon line) had all evacuated. Free black women and children, both historians say, were kidnapped in droves by Confederates raiding nearby towns in the weeks before the battle. Declared "contrabands" in official orders, they were herded south. For varied reasons - chiefly the triumph of pro-Southern post-war history, or "Tara"-vision - this incident has been omitted from most accounts. But Sears and McPherson cite witnesses of the pogrom, such as the white diarist Rachel Cormany.

One wishes "Hallowed Ground" were longer; some might wish Sears had shortened his account - although its comprehensiveness pays off when he recounts the battle's climax - Pickett's charge - from a score of angles. Both Sears and McPherson have lived with this subject for a lifetime and have thought hard about communicating it as clearly as possible. Like 19th-century scholars, rather than modern or postmodern ones, they know citizens will respond to serious matter if given half a chance by lucid presentation. Sometimes, they show, writers succeed by staying behind the times.

• Tom O'Brien frequently writes for the Saturday Civil War section of The Washington Times.