William Schouler, A history of Massachusetts in the Civil War: Volume 1

On July 1, General Banks, with his command, was in front of Port Hudson, on the Mississippi. General Grant was besieging Vicksburg, which fell into his hands July 4. Port Hudson capitulated a few days subsequent; and the Army of the Potomac was advancing, by forced marches through Virginia, across the Potomac into Pennsylvania, to head off Lee, who had advanced with his entire command, by a flank movement, into that State.

The armies met on the second and third days of July, at Gettysburg, when the great battle of the war was fought, and the most important victory gained by the Union arms. The defeat of the rebel army at Gettysburg, the capture of Vicksburg by General Grant, and the fall of Port Hudson, culminating as they did within a few days of each other, were the most important events which had happened during the war; they gave strength and courage to the Union cause, and weakened and discouraged the enemy. Lee was driven back behind his fortifications in Virginia, south of the Rapidan; the Mississippi was ours; the Southern Confederacy was severed; and from that time until the close of the Rebellion, in the spring of 1865, it lost strength and prestige.

The battle of Chancellorsville was fought May 4, when the Army of the Potomac was under command of General Hooker, from whom successful military operations had been expected. On the first day of May, he commenced his advance movement across the Rappahannock. The loyal people of the nation hailed the advance as an event sure to result in success,—the defeat of Lee's army, and the capture of Richmond. Their expectations were sadly disappointed. The battle of Chancellorsville was a defeat to the Union arms; and the retreat of the army across the Rappahannock to its original quarters, the long lists of killed and wounded published in the papers, and the many rumors which reached us from the front, added to the general feeling of disappointment and sorrow which pervaded loyal hearts. In order to ascertain from an official source the true cause and the exact position of affairs, Governor Andrew