Fort Sumter fell on April 14, 1861. On the 15th Lincoln called for 75,000 troops. On the 19th Grant organized a little company in Springfield, Illinois. Two days later Governor Yates made him colonel. On the 31st of July he was in command at Mexico, Missouri. On the 7th of August his victory at Columbus won him the rank of brigadier-general. On the 10th of February, 1862, he was made major-general; on the 23d of March, 1864, he was made lieutenant-general of the armies of the United States. It was one long uninterrupted series of victories, for it has been said that it will never be known if Grant could conduct a retreat, because he never was defeated. From the beginning his supreme qualities as a military commander were fully evidenced. Columbus was called the Gibraltar of the Mississippi. Halleck had ordered Grant to feel the strength of the enemy. But Grant was resourceful, fertile in expedients, a believer in offensive tactics. Hurling his forces upon Columbus, he won a signal victory. At Fort Donelson, Grant showed his iron endurance and untiring patience. When it came to the critical hour of the assault, a cold sleet-storm fell upon his army; the ground was a sheet of glass, the trees encased in ice. Grant himself spent half the night under a tree, standing upright, receiving reports and working out his plans. When a spy brought word that the Confederates had packed their knapsacks with three days' rations, Grant said: "They are preparing to retreat; we must assault the works," and, despite the storm, made an immediate attack. When Halleck received the news of the fall of Fort Donelson, in announcing the victory to Washington he did not even mention the name of Grant, but asked Lincoln to promote Smith, a subordinate commander. Later, in 1863, after months of siege by river and by land, came the capture of Vicksburg, coincident with the Battle of Gettysburg, that was the high-water mark of the war. The announcement of these two victories, on July 4, 1863, intoxicated the North with joy.