Growing up in Texas, I studied the state's history in 5th, 7th, and 12th grades of public school. I know the stories of Stephen Austin's colony, the Alamo, the Battle of San Jacinto, and the years of the Republic of Texas quite well. The presentation was always, of course, from the viewpoint of the victors. In A Glorious Defeat, Timothy J. Henderson examines the Mexican part in the war or wars. (Do you count the Texas Revolution as part of the U.S. War with Mexico?) Rather than assign blame, he examines the social, economic, and political forces in Mexico leading up to and existing through the war. Then he describes the legacy for both countries.
The central point is that many Mexican leaders knew that their country would lose the war before the fighting ever started. The young country, independent from Spain for only fifteen years when the Texas colonists rebelled, was poor, sparsely populated, and politically divided. The liberals wanted to form a democracy, while the conservatives wanted to establish a European style monarchy. The political sides only agreed that the United States was taking advantage of their country's weakness. Most of the leaders foresaw the inevitable loss of Texas, New Mexico, and California. So, why did they reject U.S. purchase offers and fight a losing battle?
According to Henderson, fighting the U.S. was seen by the Mexicans as patriotic and opposing the war became politically suicidal. Few dared to speak up, and they were exiled or executed. As a result, the military drafted poor and native peoples (few of the landed or merchant classes served) and sent them on military campaigns without weapons, food, or clothing. Many died of starvation or disease before battle. Desertion was rampant.
While Henderson concentrates on telling the story of the country as a whole, he does include tales of key figures, such as Antonio Lopez de Santa Anna, Vicente Guerrero, and Anastacio Bustamente. The saddest of the stories is about General Manuel de Mier y Teran, who commits suicide rather than see all his grim predictions come true.
Many public libraries are short on materials about this war that preceded and in ways led to the American Civil War. It is a good purchase and a good read.
Henderson, Timothy J. A Glorious Defeat: Mexico and Its War with the United States. New York: Hill & Wang, 2007. ISBN 9780809061204