After defeating the Union Army of Virginia at Bull Run, Lee led his Confederate Army of Northern Virginia into Maryland beginning his Maryland Campaign. He had several reasons for attacking the North. First, it was harvest time in the Shenandoah Valley and Lee needed to turn the Union's attention away from his main sources of food for his army. Secondly, he needed European support for the Confederacy. A major win in the North could get the support they needed and also cause the border state of Maryland to secede. It would demoralize the North and possibly get them to negotiate. Lee thought the Union army needed time to rebuild and resupply and moving quickly he could catch them unprepared.