Jackson's Valley Campaign in the spring of 1862 was a tremendous success. In just 48 days, his approximately 17,000 Confederates had marched up and down the Shenandoah Valley. They engaged and defeated three different Union armies totaling about 52,000 men. Jackson kept them from reinforcing McClellan's army on the Virginia Peninsula. The campaign cost the Union 5,735 casualties at a loss of about 2,441 Confederate casualties. They captured so many supplies from Banks' army that Confederate soldiers began referring to the Union general as "Commissary Banks."