The hero of the Battle of Cerro Gordo, the Thermopylae of the Mexican War, was a captain in the Engineer Corps named Robert E. Lee.

On a horse named Creole, Lee led American troops in a stealthy march across treacherous terrain, positioning them in the rear of the Mexican army and cutting off all escape routes.

The battle plan for Cerro Gordo, according to 2nd Lt. Ulysses S. Grant, had unfolded exactly as it had been drawn up.

Along with Lee and Grant, dozens of other officers who later served with distinction in the Civil War got their first taste of combat in the Mexican War.

		"THE TRAINING GROUND: GRANT, LEE, SHERMAN AND DAVIS IN THE MEXICAN WAR, 1846-1848" By Martin Dugard Little, Brown ($29.99)

Martin Dugard, a freelance writer, seeks to understand how the experiences of these young men in a war waged on foreign soil that nearly doubled the size of the United States "molded them" into military tacticians and strategists a decade and a half later.

The book is a bit of a bait-and-switch. Dugard delivers an old-fashioned military history of the Mexican War, crediting Gens. Zachary Taylor and Winfield Scott for defeating an enemy that almost always outnumbered the American forces. And he provides detailed descriptions of army life.

Dugard, however, sheds little light on the war as, well, a training ground. The protagonists -- Grant, Lee, William Tecumseh Sherman and Jefferson Davis -- disappear for long stretches. When they surface, they are very much "in the moment," and, beyond the obvious, Dugard isn't able to extract much of significance to their subsequent careers from what they say or do.

Consider Dugard's treatment of Robert E. Lee. After laboring in "engineering anonymity," building fortifications, Lee saw combat and the aftermath of a siege in the Mexican War. Cerro Gordo, Dugard writes, "left him a changed man." Aware now of the impact of cannon fire on the human body and the impact of war on noncombatants, Lee "would never view war the same way again."

Would he conduct war any differently? Dugard doesn't say.

During the war, Dugard suggests, Grant completed his evolution "from timid young lieutenant to future general." Now able to "see the entire battlefield in his head," he had become a master tactician, convinced that offensive movement was preferable to defensive entrenchment, and able to see flaws even in the sophisticated plans of Winfield Scott.

These two splendid pages on Grant are too little and come too late. The role of the soon-to-be fratricidal band of West Point brothers in the Mexican War may well have been "pivotal" to their maturation as military men in the Civil War, but "The Training Ground" leaves us still wondering about the lessons they learned and how they applied them to the vastly different circumstances of the bigger war that followed.