Controversial and unpopular, the U.S.-Mexican War divided the country's loyalties more than any event at the time since the Revolution. Abraham Lincoln argued against it in Congress; Henry David Thoreau went to jail rather than pay taxes that would help to finance it. The only public issue that rivaled the U.S.-Mexican War for bitterness of debate was slavery and slavery played an important role in starting the conflict. But the realities of the time were powerfully shaped by the belief in the myth of "Manifest Destiny that the United States was predestined to occupy the North American continent "from sea to shining sea and so a war of conquest was launched. When it was over, the United States had doubled its size at the expense of Mexico, which had shrunk by half.

A fast-moving narrative filled with evocative and historically accurate detail, U.S.-Mexican War, Updated Edition tells the full story of a long ignored but critical passage in American military history that was soon overshadowed by the Civil War. New box features cover topics such as early 19th-century Mexican politics; the roles slavery and "Manifest Destiny played in bringing about the war; and Winfield Scott's struggle to create a professional U.S. Army.