I think that you refer to J E B Stuart.
I certainly don't think that he was one of the greatest commanders of all time (this post was prompted by your mention of Jeb Stuart), but I just finished watching a documentary about General George A. Custer, and I had no idea he was such a major figure in the Civil War. According to the documentary, he modeled some of his cavalry tactics after the success of Jeb Stuart.
He led an interesting life (was promoted to General at age 23), and even more interesting now is that he is perceived to be such a racist, idiotic villain.