▁it ▁to ▁be ▁am put ated . ▁Although ▁the ▁Confeder ates ▁were ▁techn ically ▁the ▁vict ors , ▁driving ▁Rose cr ans ▁from ▁the ▁field , ▁B rag g ▁had ▁not ▁achieved ▁his ▁object ives ▁of ▁destroy ing ▁Rose cr ans ▁or ▁of ▁rest oring ▁Confeder ate ▁control ▁of ▁East ▁Tennessee , ▁and ▁the ▁Confeder ate ▁Army ▁suffered ▁cas ual ties ▁that ▁they ▁could ▁ill ▁afford . ▁ ▁Re actions ▁and ▁effects ▁ ▁On ▁September ▁ 2 1 , ▁Rose cr ans ' s ▁army ▁with d rew ▁to ▁the ▁city ▁of ▁Ch att ano oga ▁and ▁took ▁advantage ▁of ▁previous ▁Confeder ate ▁works ▁to ▁ere ct ▁strong ▁def ensive ▁positions . ▁However , ▁the ▁supply ▁lines ▁into ▁Ch att ano oga ▁were ▁at ▁risk , ▁and ▁the ▁Confeder ates ▁soon ▁occupied ▁the ▁surrounding ▁height s ▁and ▁laid ▁sie ge ▁upon ▁the ▁Union ▁forces . ▁Unable ▁to ▁break ▁the ▁sie ge , ▁Rose cr ans ▁was ▁rel ieved ▁of ▁his ▁command ▁of ▁the ▁Army ▁of ▁the ▁C umber land ▁on ▁October ▁ 1 9 , ▁replaced ▁by ▁Thomas . ▁McC ook ▁and ▁C ritt enden ▁lost ▁their ▁commands ▁on ▁September ▁ 2 8 ▁as ▁the ▁XX ▁Corps ▁and ▁the ▁XX I ▁Corps ▁were ▁cons olid ated ▁into ▁a ▁new ▁IV ▁Corps ▁commanded ▁by ▁Gr anger ; ▁neither ▁officer ▁would ▁ever ▁command ▁in ▁the ▁field ▁again . ▁On ▁the ▁Confeder ate ▁side , ▁B rag g ▁began ▁to ▁w age ▁a ▁battle ▁against ▁the ▁sub ordinates ▁he ▁res ented ▁for ▁failing ▁him ▁in ▁the