Lee was actually quite even-minded in his racial tolerance, as was much of Virginia. Three years before the war, Virginia's state legislature came very close to banning slavery in the state, though it would have been a gradual thing. Ironically, historians speculate that one of the factors that scared the Virginia Legislature away from doing this was the appearance that they had "caved in" to radical abolitionists. This was one way that the truly firebreathing abolitionists (e.g. John Brown) helped defeat their own cause - something modern pro-lifers would do well to remember!
By all unbiased accounts, Robert E. Lee was a fine Christian gentleman who was evenhanded to all and terribly torn between loyalty to his country and loyalty to his state. His nobility of character was admired by even his enemies. An indication of what kind of man he was is given by the fact that he could not tolerate cruelty to animals, and if anyone under his command was caught maltreating a beast, that man was in big trouble. He was a slaveowner, but this was common for large estate holders. By all accounts he was a just and decent slaveowner, never overworking or mistreating his people.