Two history professors (Shea: Univ. of Arkansas at Monticello; Hess: Lincoln Memorial Univ.) offer an absorbing analysis of an important early conflict in the Civil War. Though often regarded as having only peripheral strategic importance, the battle of Pea Ridge (Arkansas), the authors explain, led to Union control of Missouri and dominance of the entire trans-Mississippi region. In early 1962, a large Confederate army, assisted by a pro-Confederate governor and a secessionist state guard, posed a serious threat to Missouri's membership in the Union. As the pro-Confederate state-guard commander began an apparent retreat to obtain supplies and support from the regular Confederate army, Union forces under Samuel Curtis (who in turn was commanded by Henry W. Halleck) launched an aggressive offensive drive. Confederate President Jefferson Davis appointed Earl Van Dorn, a dashing but untalented general, as overall Confederate commander—but though Van Dorn attempted to gain the initiative, what should have been a major Confederate threat to Missouri turned instead into a Federal invasion of Arkansas when Curtis's men- -marching lightly and far from Union supply lines—attacked rather than fall back into Missouri. During the fighting at Pea Ridge (March 6-8, 1862)—which was really more a strategically unified series of separate battles than a single engagement—Curtis kept the Confederate forces separated and ultimately drove them from the field. And by the authors' account, Halleck—who is not often treated kindly by historians—emerges as the unlikely hero who conceived the vigorous Federal strategy. After the battle, Van Dorn transferred his army to the eastern side of the Mississippi, allowing the Union to contain Confederate forces there. Shea and Hess rightly contend that this early Union victory, won ``in the springtime of northern hopes,'' secured Federal domination of the Mississippi region. A thoroughly researched and well-told account of an important but often neglected Civil War encounter. (Eighteen maps.)