Lee retreated back into Virginia.
On October 26, 1862 the Army of Northern Virginia crossed the Potomac River and found shelter and supplies in the Shenandoah Valley in Virginia. They had retreated from the terrible fighting at Antietam in Maryland.
The Battle of Antietam was in Maryland in 1862. Robert E. Lee's army, the Army of Northern Virginia, took on heavy casualties. He had little choice but to retreat back to Virginia.
He and his Army crossed over the Potomac and reentered Virginia.
Their defeat by McClellan at Antietam.
The Army of Northern Virginia under Robert E. Lee
The 1862, the Battle of Antietam was fought in Maryland. The Army of Northern Virginia fought against the Army of the Potomac. It was Lee versus McClellan.
Yes, in the Battle of Antietam, the Army of the Potomac had 300 cannons. This was more than the Army of Northern Virginia which had 221 cannons. Although the North had more artillery in the Battle of Antietam, the effective use Lee's artillery helped the South from losing their entire army at Antietam.
He drove the Union soldiers out of Northern Virginia.
Retreated to Virginia, where they would soon win a decisive victory at Fredericksburg.
After the Battle of Antietam in September of 1862, Lee's Army of Northern Virginia had to retreat from Maryland back to Virginia. Lee's evacuation from Maryland, for that moment of the war ended Confederate plans to take the war to the enemy, the Union.
The Army of Northern Virginia under Robert E. Lee escaped back to Virginia due to Union General McClellan's belated and cautious pursuit.