The pressure upon McClellan to move grew stronger and indeed more justifiable month after month, and when at last, in March, 1862, McClellan did move, the story of the severest adversity to the North, of Lincoln's sorest trials, and, some still say, his gravest failures, began. Its details will concern us more than those of any other part of the war. But events in the West began earlier, proceeded faster, and should be told first. Buell could not obtain from McClellan permission to carry out his own scheme. He did, however, obtain permission for Halleck, if he consented, to send flotillas up the Tennessee and Cumberland Rivers to make a diversion while Buell, as Lincoln had proposed and as McClellan had now ordered, marched upon Eastern Tennessee. Halleck would not move. Buell prepared to move alone, and in January, 1862, sent forward a small force under Thomas to meet an equally small Confederate force that had advanced through Cumberland Gap into Eastern Kentucky. Thomas won a complete victory, most welcome as the first success since the defeat of Bull Run, at a place called Mill Springs, far up the Cumberland River towards the mountains. But at the end of January, while Buell was following up with his forces rather widely dispersed because he expected no support from Halleck, he was brought to a stop, for Halleck, without warning, did make an important movement of his own, in which he would need Buell's support. The Cumberland and the Tennessee are navigable rivers which in their lower course flow parallel in a northerly or north-westerly direction to join the Ohio not far above its junction with the Mississippi at Cairo. Fort Henry was a Confederate fort guarding the navigation of the Tennessee near the northern boundary of the State of that name, Fort Donelson was another on the Cumberland not far off. Ulysses Simpson Grant, who had served with real distinction in the Mexican War, had retired from the Army and had been more or less employed about his father's leather store in Illinois and in the gloomy pursuit of intoxication and of raising small sums from reluctant friends when he met them. On the outbreak of the Civil War he suddenly pulled himself together, and with some difficulty got employment from the Governor of Illinois as a Major-General in the State Militia (obtaining Army rank later). Since then, while serving under Halleck, he had shown sense and promptitude in seizing an important point on the Ohio, upon which the Confederates had designs. He had a quick eye for seeing important points. Grant was now ordered or obtained permission from Halleck to capture Fort Henry and Fort Donelson. By the sudden movements of Grant and of the flotilla acting with him, the Confederates were forced to abandon Fort Henry on February 6, 1862. Ten days later Fort Donelson surrendered with nearly 10,000 prisoners, after a brilliant and nearly successful sortie by the garrison, in which Grant showed, further,