- Return of the enemy to Washington -- war transferred to the frontier -- condition of Maryland -- crossing the Potomac -- evacuation of Martinsburg -- advance into Maryland -- large force of the enemy -- resistance at Boonesboro -- surrender of Harpers Ferry -- our forces reach Sharpsburg -- letter of the President to General Lee -- address of General Lee to the people -- position of our forces at Sharpsburg -- battle of Sharpsburg -- our strength -- forces withdrawn -- casualties.
The enemy having retired to the protection of the fortifications around Washington and Alexandria, Lee's army marched, on September 3d, toward Leesburg. The armies of Generals McClellan and Pope had now been brought back to the point from which they set out on the campaign of the spring and summer. The objects of those campaigns had been frustrated, and the hostile designs against the coast of North Carolina and in western Virginia thwarted by the withdrawal of the main body of the forces from those regions. Northeastern Virginia was freed from the presence of the invader. His forces had withdrawn to the entrenchments of Washington. Soon after the arrival of our army at Leesburg, information was received that the hostile troops which had occupied Winchester had retired to Harpers Ferry. The war was thus transferred from the interior to the frontier, and the supplies of rich and productive districts were made accessible to our army. To prolong a state of affairs in every way desirable, and not to permit the season for active operations to pass without endeavoring to impose further check on our assailant, the best course appeared to be the transfer of our army into Maryland. Although not properly equipped for invasion, lacking much of the material of war, and deficient in transportation, the troops poorly provided with clothing, and thousands of them without shoes, it was yet believed to be strong enough to detain the opposing army upon the northern frontier until the approach of winter should render its advance into Virginia difficult, if not impracticable. The condition of Maryland encouraged the belief that the presence of our army, though numerically inferior to that of the North, would induce the Washington government to retain all its available force to provide against contingencies which its conduct toward the people of that state gave reason to apprehend. At the same time it was hoped that