=476. Military Organization in the West.=—Activities in the field began with very vigorous movements in the West. The Confederates, under General Albert Sidney Johnston (§ 478), had established a strong line in southern Kentucky, extending from Columbus to Mill Spring. They had also constructed, as already described (§ 461), two strong forts in Tennessee, just south of the Kentucky line,—Fort Henry on the Tennessee River, and Fort Donelson on the Cumberland. The organization of the Northern army in the West introduced a change in the spring of 1862. The Department of the Mississippi, which included Missouri, Arkansas, and so much of Kentucky as was west of the Cumberland River, under Major General H. W. Halleck, and the Department of the Ohio, which included the eastern parts of Kentucky and Tennessee, under Major General Don Carlos Buell, were consolidated on the 11th of March, 1862, into one department, and placed under Halleck, who thus received command of all the forces throughout the West, consisting of somewhat more than one hundred thousand men. Ulysses S. Grant,[208] who began his distinguished career in this war as colonel, had been advanced to brigadier general in consequence of a prompt and successful seizure of Cairo, and was now, though under the direction of Halleck, in command of the middle branch of the army, while Buell commanded the eastern section. [Illustration: OPERATIONS IN THE WEST, 1862] [Illustration: GENERAL ULYSSES S. GRANT.] =477. First Advances.=—The first advance in Kentucky was made by one of Buell’s divisions under General George H. Thomas, who, on the 19th of January, defeated a force of about equal numbers under General Zollicoffer at Mill Spring and drove it back into Tennessee. Rear Admiral A. H. Foote, with a fleet of gunboats, in February advanced up the Tennessee River, and, after a severe engagement, took Fort Henry, with the commanding general and a part of the garrison as prisoners. Grant, who arrived with his army at about the same time, marched rapidly across the country and surrounded Fort Donelson, on the Cumberland. After making rapid preparations for a siege, he carried the outer works of the fort by storm, and then refused to accept any terms but “unconditional surrender.” He took some fifteen thousand prisoners (February 16), including two generals, and about twenty thousand stand of arms. This was the first great victory for the North, and the skill and vigor shown attracted the attention of the whole country. The Confederate line was in consequence so broken that the troops of the Confederacy were obliged to draw back into southern Tennessee. The Union forces soon occupied Nashville, and President Lincoln appointed Andrew Johnson, a prominent Tennessee Unionist, as military governor. Grant advanced to Nashville without waiting for orders, or even reporting the nature of his movement to Halleck. The consequence was a formal