Had it not been for the stoic firmness of Mr. Lincoln in standing by Grant, which resulted in the speedy capture of Vicksburg, it is hard to predict what would have been the consequences. If nothing worse, certain it is that President Lincoln would have been deposed, and a dictator would have been placed in his stead as chief executive until peace could be restored to the nation by separation or otherwise. Mr. Lincoln thus expressed himself shortly before his death: "If I had done as my Washington friends, who fight battles with their tongues at a safe distance from the enemy, would have had me do, Grant, who proved himself so great a captain, would never have been heard of again." That Mr. Lincoln sought to interfere as little as possible with the military affairs after General Grant took charge of the army will be shown by the following letter:-- EXECUTIVE MANSION, WASHINGTON, April 30, 1864. LIEUTENANT-GENERAL GRANT,--Not expecting to see you before the spring campaign opens, I wish to express in this way my entire satisfaction with what you have done up to this time, so far as I understand it. The particulars of your plan I neither know nor seek to know. You are vigilant and self-reliant, and [I put no] restraints or constraints upon you. While I am very anxious that any great disaster or capture of any of our men in great numbers shall be avoided, I know that these points are less likely to escape your attention than they would be mine. If there be anything wanting which is within my power to give, do not fail to let me know it. And now with a brave army and a just cause, may God sustain you! Yours very truly, (Signed) A. LINCOLN.