They were ordered to the field, and their places filled by the Georgia Reserves, an organization of boys under, and men over the military age. As General Grant aptly-phrased it, They had robbed the cradle and the grave, in forming these regiments.
to use a young person for a purpose inappropriate to his or her age
Heceleme
to use a young per·son for a pur·pose in·ap·pro·pri·ate to his or her age