This was the pivotal act of his administration; but this humane and just promise to liberate four millions of slaves, to wipe out a nation's disgrace, was followed by the darkest and most doubtful days in the history of America. Grant, in the lowlands of Louisiana, was endeavoring, against obstacles, to open the Mississippi; but, with all his energy, he accomplished nothing. McClellan's habit of growling at the President had become intolerable, and Burnside superseded him in command of the Army of the Potomac. Burnside advanced against Lee, fought him at Fredericksburg, and was repulsed with terrible disaster. Then the army broke camp for another campaign, the elements opposed, Burnside gave way to Hooker. The soldiers became disheartened, and thousands deserted to their homes in the North. The President's proclamation was now virtually a dead letter; people looked upon it and characterized it as a joke. But there came at last a break in the clouds, and on Independence Day, 1863, the star of liberty and union appeared upon the distant sky as a covenant that God had not forsaken the Prophet of the West,--the Redeemer of the Slave. I can find no more fitting words to characterize Grant's victory at Vicksburg than those which the young and brave McPherson used in his congratulatory address to the brave men who fought for the victory:-- "The achievements of this hour will give a new meaning to this memorable day; and Vicksburg will heighten the glory in the patriot's heart, which kindles at the mention of Bunker Hill and Yorktown. The dawn of a conquered peace is breaking before you. The plaudits of an admiring world will hail you wherever you go." Take it altogether it was perhaps the most brilliant operation of the war, and established the reputation of Grant as one of the greatest military leaders of any age. He, the last of the triumvirate, is passing away; and, in this connection, no apology is needed in quoting the letter which the President wrote with his own hand, and transmitted to him, on receipt of the glorious tidings:-- MY DEAR GENERAL,--I do not remember that you and I ever met personally. I write this now as a grateful acknowledgment for the almost inestimable service you have done the country. I wish to say a word further. When you first reached the vicinity of Vicksburg I thought you should do what you finally did,--march the troops across the neck, run the batteries with the transports, and then go below; and I never had any faith, except a general hope, that you knew better than I that the Yazoo-Pass expedition and the like could succeed. When you got below, and took Fort Gibson, Grand Gulf, and vicinity, I thought you should go down the river and join Gen. Banks; and when you turned northward, east of the Big Black, I thought it was a mistake. I now wish to make the personal acknowledgment that you were right, and I was wrong.