D is for Dahlgren Gun
The Dahlgren gun was mainly a navy gun it was a breech loading gun. The man in the picture is John Dahlgren the inventor of the Dahlgren gun.
E is for Eward Alexander Porter
Edward Porter was the man in charge of the enourmas arttilery barrage just before Picketts Charge at Gettysburg.
F is for Field Hospital
This Field hospital was outside of Richmond.Field hospitals were where the wounded would be transported during a battle or before they could be transfered to a more permanent hospital.