The Training Ground is an interesting, often insightful account of the experiences of U.S. Grant, Robert E. Lee, William T. Sherman and Jefferson Davis during the Mexican War. 

In effect, Dugard, an independent scholar with quite a number of books to his credit, has given us a history of the Mexican War as seen through the experiences of various U.S. Army officers, with a strong emphasis on these four. This approach is not only an interesting way to look at the war, but it sheds a great deal of light on how their wartime experiences helped shape these officers'  lives, professional careers, and, in particular, grasp of the arts and sciences of warmaking. 

Each man's service in Mexico was different. So while Lee put in an impressive performance as an engineer working directly with the brilliant Winfield Scott, and thus observing that great captain's work first hand, Davis proved adept at leading men in a desperate fight, though perhaps did not learn as much about generalship as did lee, while Grant spent most of his time learning to manage and organize supplies, though he also saw a good deal of combat, and Sherman saw no fighting at all, yet learned a great deal too. In the process, Dugard strongly strong suggests that their experience helped Grant and Sherman better understand the nature of war than either Lee or Davis.

Worth a read for anyone interested in the Civil War and the development of senior military leadership