Final answer:
Lee crossed into Maryland and fought the Battle of Antietam to achieve victory on Northern soil.
Step-by-step explanation:
Lee crossed into Maryland and fought the Battle of Antietam to achieve victory on Northern soil. The battle took place on September 17, 1862, near the town of Sharpsburg and was the first major battle of the Civil War to occur on Union soil. It remains the bloodiest single day in American history. Lee launched aggressive counterattacks against the Union forces and although outnumbered, hoped to win a decisive victory in Union territory and end the war.