 Alfred Pleasonton, commander of the Cavalry Corps at Gettysburg, reported after the battle that Tidball (and James M. Robertson, who commanded the other brigade of horse artillery)… 

"are now performing the duties of general officers with only the rank of captain, and I most urgently recommend that they be promoted to the rank of Brigadier General.The Artillery arm requires organization in the higher grades.There are no general officers who by their service are so much entitled to this distinction as Captains Robertson and Tidball."