"Here we are on the banks of the Nueces in the grand camp of the army of occupation." So wrote Lt. Napoleon Jackson Tecumseh Dana when in 1845, not many months before the outbreak of the Mexican War, he joined the white-tented encampment of General Zachary Taylor in Texas. And so he continued writing during the uncertain life of camp and campaign for the better part of the next two years. In these letters to his wife, published here for the first time, Dana provides a detailed, firsthand view of the United States' war with Mexico -- fighting off the Mexicans from within Fort Brown during...