It would be helpful to know where the man in question lived: Alabama or Mississippi. Also, since the 6th Mississippi Cavalry had been organized in 1863, I'd be surprised to find anyone referring to part of it as 'Davenport's Battalion.'

Barbiere's Alabama Cavalry Battalion, AKA Davenport's Battalion, was involved in the fighting from Montevallo to Selma. Capt. Mont. Davenport came from DeKalb County AL.