Actually there were alot more than two Former Confederates Commissioned back into the service. I have a listing of some of them on my Sons of Spanish American War Veterans Camp Website. At present the list I have consists of over 300+ veterans of the Civil War who served again in 1898. Only two former Confederates were offically put back into the U.S. Regular Army, that being Fitzhugh Lee and Joseph Wheeler who were both made Brigadier Generals, United States Army, following their U.S. Volunteer service.
Among the Confederates who served again in the Span. Am. as General Officers of United States Volunteers are:
Major General Matthew C. Butler, U.S. Volunteers, former Major General, Provisional Army Confederate States
Major General Fitzhugh Lee, U.S. Volunteers, former Major General, Provisional Army Confederate States
Major General Joseph Wheeler, U.S. Volunteers, former Major General, Provisional Army Confederate States
Brigadier General John B. Castleman, U.S. Volunteers, former Major, 2nd Kentucky Vol. Cav. Rgt.
Brigadier General Henry T. Douglass, U.S. Volunteers, this is possibly former Colonel, Confederate States Engineer Corps
Brigadier General William W. Gordon, U.S. Volunteers, former Captain & Assistant Adjutant General, Confederate States Army
Brigadier General Thomas L. Rosser, U.S. Volunteer, former Major General, Provisional Army Confederate States
Brigadier General William Calvin Oates, U.S. Volunteers, former Colonel, 15th Alabama Vol. Inf. Rgt.
Brigadier General James R. Waites, U.S. Volunteers, former 1st Lieutenant, South Carolina Artillery
The list of U.S. Volunteer Officers who were former Confederates is much, much longer. The above is only those that I know for a Fact were commissioned as General Officers of United States Volunteers.
Sorry, I know I'm a know it all, ha ha.