The Dead March is both a military history of the Mexican-American War (1846–48) and an extended critique of the way both American and Mexican historians have portrayed it. Although most of his book is preoccupied with the political, social, economic, and religious aspects of the war, historian Peter Guardino (Indiana Univ.) also provides a thorough operational history, complete with discussions of weapons and tactics and including excellent maps of each important battle.

Guardino disputes the traditional view that the Americans won because they had a strong government and a unified population, while Mexicans were riven along class, ethnic, and regional lines, which kept them from organizing an effective response to the American invasion. While not denying Mexico's history of unstable governments and military coups since it gained independence from Spain in 1821, the author maintains that Mexicans often overcame political and regional divisions and united to fight the American invaders. In his long conclusion, he reminds readers that the War of 1812 and the Civil War were hardly shining examples of American unity: the former was an unsuccessful conflict marred by regional divisions in the United States, and the latter a testament of sectional disunity among the states even a decade and a half after 1846.

In the author's view, economics is the overriding explanation for American victory over Mexico: US forces won every battle before finally occupying Mexico City and forcing a negotiated settlement in favor of the United States, a nation larger and more populous than Mexico with a per capita income about three times higher. These advantages enabled it to keep warships off both coasts of Mexico during the war and, most importantly, feed and pay its soldiers during the conflict.

Many factors, including obsolete muskets and poor quality ammunition, crippled Mexican forces. But their single most intractable problem was desertion. Mexican soldiers fled their units before and during battles and especially during retreats after losses. In fact, as Guardino repeatedly points out, Mexican generals lost battles because they could not even post individual soldiers or small detachments as sentinels to guard weak points for fear the isolated men would desert. The main motive for desertion, he emphasizes, was hunger. Mexican troops were never paid on time and often went days without food. And hungry Mexican volunteers lived with the grim knowledge that their families back home were almost certainly starving in their absence. The lack of food and money, Guardino contends, was the true reason Mexico never stood a chance against the United States.

This extremely Mexico-centered book ignores an aspect of the war that has exercised many liberal and leftist historians: opposition to the war in the United States. Henry David Thoreau and Abraham Lincoln are merely the two best known Americans who publicly denounced the conflict. Guardino is also sketchy on events in Washington: President James Knox Polk first provoked the Mexicans to attack American soldiers south of the Nueces River—the previously accepted boundary between Texas and Mexico—and then prosecuted the war to its conclusion. This same fixation on Mexico extends to the strictly military as well: mentioned only in passing are Robert E. Lee, who served as chief engineer of the invasion forces, and Ulysses S. Grant, who distinguished himself in the final battles in Mexico City. Far more attention is paid to the life and actions of Mexico's most important leader, Antonio López de Santa Anna.

Guardino commendably highlights the roles played by Mexican women at both the top and bottom of the socioeconomic ladder. Most famous are the soldaderas, "women who attached themselves to Mexican regular army units" and, wives or not, cooked the soldiers' food, carried their baggage, bound up their wounds, and "provided sexual companionship" (61–62). All this was not simply a case of female self-abnegation.

At the end of the fighting, when thousands of Americans occupied Mexico City for weeks, upper-class women faced difficult choices. While their men remained in the army or lay low during the occupation, they were obliged to deal with the Yankees. That most US soldiers were Protestants further complicated matters for both sides.

Guardino also writes about masculinity and its discontents. For American soldiers, especially those in volunteer units, serving away from their homes freed them from certain moral constraints. At home, Guardino writes, they were not allowed to get drunk, rowdy, or violent (election rallies were possible exceptions). But in Mexico, during the long periods between battles and after the fighting ended, they had many chances to misbehave. During the early campaign around the Rio Grande, such behavior extended to acts that Americans themselves described as atrocities: volunteers stole from Mexican homes, raped Mexican women, and often killed Mexican men in the process. Because volunteers refused to testify against each other (their units were raised in individual towns and counties), these crimes were seldom punished.

Although Guardino is (sometimes too) eager to explain away Mexican failings and criticize American behavior, he is scrupulously fair in his meticulous battle descriptions. And he is also aware of the ironies of the outcome of the war: the Treaty of Guadalupe Hidalgo (signed 2 Feb. 1848) gave the victors most of what later became Arizona, New Mexico, Utah, Wyoming, Nevada, Colorado, and California. These vast lands had been impossibly distant for the people of Mexico, who were concentrated in the Central Highlands; within a few short years, however, they transformed the United States.

The Dead March will educate in detail anyone interested in the Mexican-American War, Mexico in the nineteenth century generally, or the influence of gender and economics on the progress and outcomes of wars.