=461. Physical Features of the West.=—West of the Alleghanies the water courses, in some respects, were of even more importance than in the East. The Cumberland River, which rises in the mountains of the same name, flows southwest, and then, turning sharply to the north, empties into the Ohio some miles above Cairo. The Tennessee flows in the same general direction, but bends so far south as to reach Alabama and Mississippi, and then, turning northward and flowing through Tennessee and Kentucky in a course nearly parallel with the Mississippi, though in an opposite direction, discharges its waters into the Ohio. As railroads were few and other roads were poor, these navigable waters were of the utmost importance to the side that should be able to command them. Both antagonists recognized this fact, and, therefore, the first contest in this region was for command of these rivers. Soon after the war began, the Unionists took Cairo, at the mouth of the Ohio, and the Confederates constructed Forts Henry and Donelson, on the Tennessee and Cumberland rivers, at points not far from the Ohio, where the rivers were so near each other that either fort could easily reënforce the other. In this way each side hoped to gain command of the rivers for purposes of transportation. The Mississippi also was strongly fortified by the Confederates at Memphis, at Island Number 10, at Vicksburg, and at other points of less importance. West of the Mississippi, the physical features of the country were of less military consequence. DOMESTIC AND FOREIGN COMPLICATIONS. [Illustration: CONFEDERATE FLAG.]