To-day came the order relieving General Hooker, who issued the following characteristic farewell address to the troops, many of whom were taken, wholly by surprise, and all of them appeared greatly afflicted: HEADQUARTERS ARMY OF THE POTOMAC, Frederick, Md., June 28, 1863. In conformity with the orders of the War Department, dated June 27, 1863, I relinquish the command of the Army of the Potomac. It is transferred to Major-General George G. Meade, a brave and accomplished officer, who has nobly earned the confidence and esteem of the army on many a well-fought field. Impressed with the belief that, my usefulness as the commander of the Army of the Potomac is impaired, I part from it, yet not without the deepest emotions. The sorrow of parting with the comrades of so many battles is relieved by the conviction that the courage and devotion of this army will never cease nor fail; that it will yield to my successor, as it has to me, a willing and hearty support. With the earnest prayer that the triumph of this army may bring successes worthy of it and the nation, I bid it farewell. JOSEPH HOOKER, _Major-General_. Such a change of _regime_ on the eve of a great battle, with the command in the hands of one less known and trusted, at first seemed to threaten disaster. But the modest, earnest words with which the new commander framed his first order to the troops allayed all fears, renewed confidence, and greatly attached to him the hearts of his subordinates. HEADQUARTERS ARMY OF THE POTOMAC, June 28, 1863. By direction of the President of the United States I hereby assume command of the Army of the Potomac. As a soldier, in obeying this order --an order totally unexpected and unsolicited--I have no promises or pledges to make. The country looks to this army to relieve it from the devastation and disgrace of a hostile invasion. Whatever fatigues and sacrifices we may be called to undergo, let us have in view constantly the magnitude of the interests involved, and let each man determine to do his duty, leaving to an all-controlling Providence the decision of the contest. It is with just diffidence that I relieved, in the command of this army, an eminent and accomplished soldier, whose name must ever appear conspicuous in the history of its achievements; but I rely upon the hearty support of my companions in arms to assist me in the discharge of the duties of the important trust which has been confided to me. GEORGE G. MEADE, _Major-General Commanding_.