Men of the 43rd Battalion, 1st Virginia Cavalry AKA Mosby’s Rangers
Colonel John Singleton Mosby is sat on the second row, third from the right.
Colonel John Singleton Mosby of the Confederate Army and Commanding Officer of the 43rd Battalion, 1st Virginia Cavalry or “Mosby’s Rangers”.
Mosby apparently said of this photograph, that it was his favourite according to http://www.findagrave.com/cgi-bin/fg.cgi?page=pv&GRid=3080&PIpi=18908470
But I cannot confirm this.
A Daguerreotype (I believe) of a Confederate Cavalry Trooper.