Combing through historical records, it appears that Robert E. Lee himself also opposed the erection of Confederate monuments…

 

“As regards the erection of such a monument as is contemplated, my conviction is, that, however grateful it would be to the feelings of the South, the attempt, in the present condition of the country, would have the effect of retarding instead of accelerating its accomplishment, and of continuing if not adding to the difficulties under which the Southern people labor.” (R. E. Lee, 1866)

Source: Jones, J. William 1836-1909. Personal Reminiscences, Anecdotes, and Letters of Gen. Robert E. Lee. United States: 1875, p.257