Read Shea and Hess's Pea Ridge: Campaign in the West last weekend. Excellent read, dunno about the historical accuracy. (Pea Ridge was a battle in March 1862, in northwestern Arkansas just that side of the Missouri border.) TransMississippi Civil War history is pretty thin on the ground. The salient points from the book is as follows: Confederate Major General Van Dorn was criminally incompetent, Union General Curtis was excellent, and Union General Sigel was a really interesting flake.
Sigel was a German immigrant-politician without any serious training or talent for war. He had been involved in the 1848 revolutions, which led people to think that he had more military experience than he actually did, and was something of a charismatic. This meant that he was a typical "political" general - promoted through connections and his popularity with voters, rather than any actual skills or performance. His military instincts, in fact, were almost always disastrous. The summer before Pea Ridge, he talked Lyon into dividing his tiny army in an ill-advised attack against a superior enemy at Wilson's Creek, which got Lyon killed. Sigel went on to bumble the rest of his career after Pea Ridge, finally being put on the shelf after a particularly embarrassing defeat in the Shenandoah Valley at New Market in 1864.
Sigel seemed to possess one military talent, and that was for retreat. During the initial advance of Van Dorn's overwhelmingly superior force on a town in northwestern Arkansas called Bentonville, Sigel got his main force away with plenty of time to spare, but then left his rear guard in the town, apparently so that he could showboat in the face of the on-rushing Rebel cavalry. After putting himself and his rear guard in an impossible situation, he managed to cut his way out through an improbable series of skirmishes and wild chases, suitable for the silliest of historical action movies.
Sigel's performance on the second day of Pea Ridge illustrated yet again what he was capable of when he thought he was retreating. Van Dorn had stupidly marched his starving force off their feet, but his army collapsed square across the Union Army of the Southwest's sole line of communication, supply, and retreat. The commanding Union general, Curtis, was well aware that he had Van Dorn's exhausted, half-defeated force on the ropes after a day of fighting, but Sigel, being an uneducated, excitable politician, was convinced that the Union army was doomed, and only he could save it by cutting a line of retreat back into Missouri. Since the highly competent Curtis had concentrated the Union army in an advantageous position, and left the excitable Sigel in charge of his wing, conditions had been set for the following action, but you have to give Sigel credit - he did the fighting. Van Dorn had a three-to-two advantage in infantry, and a two-to-one advantage in artillery, but Sigel actually put his artillery to use, and orchestrated an improbably masterful combined artillery-infantry advance, his batteries smashing Confederate batteries as they were fed piecemeal into the battle, and, driving the Confederate infantry back from their positions, allowing a triumphal rush by the well-marshaled and enthusiastic Union infantry.
This is distinctive, because it's one of exactly two cases of massed artillery succeeding in an offensive assault. Sigel's Napoleonic tactics of staggered battery advances weren't supposed to work on a battlefield dominated by rifled musket fire. It probably happened because Van Dorn had offered battle dozens of miles from his trains, and had mis-placed his supplies - his troops were not only starving, but also out of ammunition. Nevertheless, Sigel, who thought he was cutting his way through for a general retreat, smashed the Confederates as they began to retreat, themselves. As Van Dorn slipped off to the east, Sigel drove directly north, hell-for-leather, nominally chasing routed fragments of the enemy, but in actuality pursing a pre-planned retreat. It took the better part of a day for Curtis to retrieve his wayward second-in-command, by which time, the Rebels had literally disappeared in the usual post-battle rain and bitter cold.
Confederate Brigadier General Rains bitterly complained to his troops that "the only one whipped at Pea Ridge was Van Dorn"; unfortunately for Rains, he made this observation in earshot of Van Dorn, who had him put under arrest. But Rains had a point. The Confederates rarely enjoyed a numerical and positional advantage like that at Pea Ridge; it took a general with Van Dorn's unique anti-genius to produce such a preposterous reversal, to such a preposterous victor.