Was Robert E. Lee A Great General?

A man's greatness can be seen in the virtue he possess and  not by the battles he has lost.The same was the case with General Lee,who was the commander of southern forces in the American Civil War.He fought for the abolition of slavery.When in 1861,this civil war broke out as Lincoln,the US president did not allow this right to the states.There was severe bloodshed and destruction all over the region..In 1863 a part of southern forces were defeated at Gettysburg and with this Abraham Lincoln proclaimed the abolition of slavery.The remnants of the southern forces surrendered to General Grant,the Commander of Union forces in 1865 as there was no use of continuation of war ,their demanded right was achieved i.e abolition of slavery.In that perspective ,General Robert Edward Lee was indeed a great General.