Burg's Indisputable ranking of Generals from the American Civil War based on MILITARY Aptitude ONLY:

tie 1) William T. Sherman USA
tie 1) Nathan Bedford Forrest CSA
3) Stonewall Jackson (would have been #1 had he lived and if not for his performance in the Seven Days Battle, 1862)
4) Robert E. Lee CSA
5) US Grant USA
6) Patrick Cleburne CSA
7) George H. Thomas USA

But no General was as Beloved as Robert E. Lee