In several ways, 1862 was the war's most pivotal year. This was the year that marked Robert E. Lee's elevation to field command of the Army of Northern Virginia and began his run as the most successful Confederate general and one of the most legendary tacticians in American military history. Lee's sucesses were so extraordinary that by the autumn of 1862, the Confederates had shifted from the defensive and were attempting to invade Union-occupied areas across the border regions. The year also witnessed the transformation of Union war aims from preservation of the Union to emancipation of the slaves --a striking and wrenching decision that occupied most of 1862.