After months of reverses, the Union army went on the offensive in the early spring of 1862. In Virginia, General McClellan prepared for his Peninsula Campaign; in Tennessee, General Grant had captured Forts Henry and Donelson; and in southwestern Missouri, General Samuel R. Curtis had driven Sterling Price and his Missouri State Guard out of the state and into the arms of General Ben McCulloch's Confederate army in northwestern Arkansas. Using the united armies of Price and McCulloch, the new Confederate department commander, Earl Van Dorn, struck back at Curtis's Federal army, outnumbered and two hundred miles from its supply base. Two days of fighting in the wilds of the Ozark Mountains at a place called Pea Ridge decided control of northern Arkansas and southern Missouri for the rest of the war. 86945868