While Colonel Grant was at Caseyville it was reported that Quincy, on the Mississippi, was menaced by rebel guerillas from Missouri, and he was ordered to the exposed point. In the absence of transportation he marched his regiment one hundred and twenty miles of the distance. From this point his command was sent into Missouri, where the discipline and the morals of the body were improved by quiet and judicious measures. Guarding railroads was the service in which the regiment was employed; and when serving with other commands Grant was the acting brigadier-general, though he was ranked by all the other colonels.
In July of the opening year of the war Grant became a brigadier-general of volunteers. The appointment was obtained by Mr. Washburn, who had befriended him before. The Western Department was at this time under the command of General Fremont. Grant's district was a part of Missouri, with Western Kentucky and Tennessee, and he established his head-quarters at Cairo, a point of the utmost military importance as a depot of supplies and a gunboat rendezvous. Kentucky had proclaimed a suspicious neutrality, and near Cairo, on the other side of the river, were the three termini of a railroad from the South. A Confederate force seized two of them, and Grant hastened to secure Paducah, the third. The enemy hurriedly retired as he landed his force, and Grant issued a temperate and judicious proclamation, for he was on the soil of the enemy. He had acted without orders from his superior, and returning to Cairo after an absence of less than a day, he found Fremont's order, already executed, awaiting him. He also took possession of Smithland, at the mouth of the Cumberland River.
With a force of 3,100 men General Grant made an incursion into Missouri to break up a rebel camp at Belmont, where he fought his first battle in the Rebellion. He had accomplished his purpose, when the enemy was reinforced from Columbus, on the other side of the river, and though he brought off his command in safety he narrowly escaped capture himself. Fremont was superseded by Halleck, and for the next two months Grant was employed in organizing and drilling troops. Columbus, with 140 cannon and full of men and material, closed the Mississippi. The Confederate line of defence against the invasion of the South extended from this point across the country, including Fort Henry on the Tennessee and Fort Donelson on the Cumberland, the latter mounting forty guns, with quarters for 20,000 soldiers.
Grant was studying this line of defence, devising a plan to break through it. By order of General Halleck he had sent out a reconnoissance in force, under General Smith, who reported to him that the capture of Fort Henry was practicable. Grant forwarded this report to the commander of the department, and asked for permission to attack it. This was refused in sharp and curt terms. A written application, earnestly seconded by Commodore Foote, who had brought the gunboat service up to a state of efficiency in the West, secured the desired order. With 17,000 men, in connection with 7 gunboats under the command of the commodore, Grant started upon his mission the day after he received the order. Fort Henry was captured, though the army was not engaged. The main body of the Confederate force escaped to Fort Donelson.
The capture of Fort Henry cheered the army and the people. Grant telegraphed the result of the attack to Halleck, and announced his intention to proceed against Fort Donelson. Leaving 2,500 men to garrison the fort, Grant marched with 15,000 from Fort Henry, while a considerable addition to his force came up the river. The fortification was invested, and after three days of persistent fighting in cold, snow, and hunger, the fort surrendered. The gunboats were severely handled by the water batteries of the enemy, and the commodore was badly wounded, so that most of the work fell upon the army.
It was a brilliant victory, and the loyal nation resounded with the praises of Grant. This was the pointer to the fame he afterward achieved. His reply to the rebel general, "I propose to move immediately on your works," was repeated all over the country, and the initials of his name came to mean "Unconditional Surrender," the terms he had demanded of the commander of the fort.
The strategetic line of the Confederates was broken, and new dispositions of their forces became necessary on account of this important victory; Columbus was abandoned, and its men and material sent to Island No. 10. The battle of Pittsburg Landing, or Shiloh, as it is called in the South, followed under Grant's command. It was a bloody and hotly contested action, and not as decisive as that of Donelson. The ground was held, and the arrival of Buell with reinforcements caused the Confederates to retire. Sherman had a command in this battle under Grant, and the strong friendship between these two great commanders, which subsisted to the end, had its origin about this time.
Not such were the relations between Halleck and Grant, for the latter was practically thrown into the shade by the former; but the hero of Fort Donelson continued to do his duty faithfully, making no issue with his superior. At this time he was in command of the Army of the Tennessee. While he remained in this position the Union army and navy had made decided progress in the West and the South; but no real advance was made in the direction of the rebel capital. Then McClellan was removed from his position of general-in-chief, and Halleck was appointed in his place. Grant seemed to be forgotten for the time, or his operations were overshadowed by those in the East. But he had driven the enemy out of West Tennessee, and was turning his attention toward Vicksburg.
When he had sufficiently informed himself in regard to the situation, he proposed to the general-in-chief a movement upon Vicksburg, which was really the Gibraltar of the Mississippi, and he was invested with full powers to carry out his own plans. Constantly and earnestly supported by Sherman, he battered against this strong fortress for six months. Various expedients were resorted to for the reduction of the place, without success. With the written protest of four of his ablest generals in his pocket, Grant moved his army to a point four miles below Grand Gulf, fought several battles on his way, and came to the rear of Vicksburg. The Confederate engineers were doubtless as skilful as any in the world, and seemed to be justified in regarding the fortress, with its surrounding batteries, fortifications, swamps, and tangled jungles, as impregnable.
Following up his regular siege operations, Grant exercised his indomitable will against those tremendous defences, and Vicksburg fell. The news of its surrender was spread all over the loyal nation with that of the great victory of Gettysburg. The Confederacy had been cut in two, and a decided turn in the struggle for the Union was clearly indicated. The name of the victorious general was again upon the lips of all the people. Grant himself seemed to be the only man who remained unmoved. President Lincoln sent him an autograph letter, acknowledging that Grant was right while he was wrong; and even Halleck was magnanimous enough to send him a very handsome letter of congratulation. The fortunate general had been made a major-general of volunteers after his victory at Donelson; and he was now promoted to the rank of major-general in the regular army.