3. The forces left for the defense of Washington will be placed in command of Brigadier-General James S. Wadsworth, who shall also be military governor of the District of Columbia. 4. That this order be executed with such promptness and dispatch as not to delay the commencement of the operations already directed to be undertaken by the Army of the Potomac. 5. A fifth army corps, to be commanded by Major-General N.P. Banks, will be formed from his own and General Shields's (late General Lander's) divisions. ABRAHAM LINCOLN. PRESIDENT'S GENERAL WAR ORDER No. 3. EXECUTIVE MANSION, _Washington, March 8, 1862_. _Ordered_, That no change of the base of operations of the Army of the Potomac shall be made without leaving in and about Washington such a force as in the opinion of the General in Chief and the commanders of all the army corps shall leave said city entirely secure. That no more than two army corps (about 50,000 troops) of said Army of the Potomac shall be moved _en route_ for a new base of operations until the navigation of the Potomac from Washington to the Chesapeake Bay shall be freed from enemy's batteries and other obstructions, or until the President shall hereafter give express permission. That any movements as aforesaid _en route_ for a new base of operations which may be ordered by the General in Chief, and which may be intended to move upon the Chesapeake Bay, shall begin to move upon the bay as early as the 18th day of March instant, and the General in Chief shall be responsible that it so move as early as that day. _Ordered_, That the Army and Navy cooperate in an immediate effort to capture the enemy's batteries upon the Potomac between Washington and the Chesapeake Bay. A. LINCOLN. PRESIDENT'S SPECIAL WAR ORDER No. 3 EXECUTIVE MANSION, _Washington, March 11, 1862_. Major-General McClellan having personally taken the field at the head of the Army of the Potomac, until otherwise ordered he is relieved from the command of the other military departments, he retaining command of the Department of the Potomac. _Ordered further_, That the departments now under the respective commands of Generals Halleck and Hunter, together with so much of that under General Buell as lies west of a north and south line indefinitely drawn through Knoxville, Tenn., be consolidated and designated the Department of the Mississippi, and that until otherwise ordered Major-General Halleck have command of said department. _Ordered also_, That the country west of the Department of the Potomac and east of the Department of the Mississippi be a military department, to be called the Mountain Department, and that the same be commanded by Major-General Frémont. That all the commanders of departments, after the receipt of this order by them, respectively report severally and directly to the Secretary of War, and that prompt, full, and frequent reports will be expected of all and each of them. ABRAHAM LINCOLN.