aca , ▁and ▁constructed ▁def ensive ▁positions . ▁However , ▁after ▁a ▁brief ▁battle , ▁John ston ▁again ▁yield ed ▁to ▁Sh erman , ▁and ▁retre ated ▁from ▁Res aca ▁on ▁May ▁ 1 5 . ▁John ston ▁assemble d ▁the ▁Confeder ate ▁forces ▁for ▁an ▁attack ▁at ▁Cass ville . ▁As ▁his ▁troops ▁advanced , ▁an ▁enemy ▁force ▁of ▁unknown ▁strength ▁appeared ▁unexpected ly ▁on ▁his ▁right ▁fl ank . ▁A ▁sk irm ish ▁en su ed , ▁forcing ▁the ▁corps ▁commander , ▁L t . ▁Gen . ▁John ▁Bell ▁H ood , ▁to ▁halt ▁his ▁advance ▁and ▁re position ▁his ▁troops ▁to ▁face ▁the ▁threat . ▁Fac ed ▁with ▁this ▁unexpected ▁threat , ▁John ston ▁abandoned ▁his ▁attack ▁and ▁renew ed ▁his ▁retre at . ▁On ▁May ▁ 2 0 ▁they ▁again ▁retre ated ▁ 8 ▁miles ▁further ▁south ▁to ▁Car ters ville . ▁The ▁month ▁of ▁May ▁ 1 8 6 4 ▁ended ▁with ▁Sh erman ' s ▁forces ▁attempting ▁to ▁move ▁away ▁from ▁their ▁rail road ▁supply ▁line ▁with ▁another ▁turning ▁movement , ▁but ▁became ▁bog ged ▁down ▁by ▁the ▁Confeder ates ' ▁fier ce ▁def enses ▁at ▁the ▁Battle ▁of ▁New ▁Hope ▁Church ▁on ▁May ▁ 2 5 , ▁the ▁Battle ▁of ▁Pick ett ' s ▁Mill ▁on ▁May ▁ 2 7 , ▁and ▁the ▁Battle ▁of ▁Dallas ▁on ▁May ▁ 2 8 . ▁ ▁In ▁June ▁Sh erman ' s ▁forces ▁continued ▁man eu vers ▁around ▁the ▁northern ▁approaches ▁to ▁Atlanta , ▁and ▁a ▁battle ▁en su