My research into Confederate reactions to the presence of USCTs at the Crater leaves little doubt that one of their primary fears was that defeat would lead to the overturning of a slave society. From their perspective this outcome had nothing at all to do with slave ownership and had everything to do with losing control of a society where the institution of slavery guaranteed the continued separation of the races along with its well-entrenched hierarchy. The archival record is very clear on this and Chandra Manning’s new book on Civil War soldiers and slavery confirms it.
While the discussion of race and slavery within the ranks has been given new life in recent historical studies, Robert E. Lee’s own racial outlook continues to suffer at the hands of people who draw overly simplistic distinctions or who fail to place Lee within the proper social-economic context. Luckily we have Lee himself who makes it very clear in a letter to Secretary of War James A. Seddon on the significance of the Emancipation Proclamation. The letter was written on January 10, 1863:
In view of the vast increase of the forces of the enemy, of the savage and brutal policy he has proclaimed, which leave us no alternative but success or degradation worse than death, if we would save the honor of our families from pollution, our social system from destruction, let every effort be made, every means be employed, to fill and maintain the ranks of our armies, until God, in his mercy, shall bless us with the establishment of our independence.
While the letters written by soldiers in the ANV who experienced the fight at the Crater were understandably much more emotional, Lee’s letter touches on the main themes. Battlefield defeat for Lee meant nothing less than an overturning of the Southern racial hierarchy, and one can assume that his reference to "pollution" has something to do with miscegenation or at least a fear of more liberal rules governing the interaction of the races.
The acknowledgment of such a racial outlook does nothing to my personal view of Lee since I am not invested in any specific moral image. He is a figure from the past who held views about slavery and race which corresponded to widely held assumptions.
Nothing surprising about that.