▁meaning less ▁post ▁on ▁rec ruit ing ▁duty ▁in ▁the ▁Trans - Miss iss ippi ▁Theater . ▁ ▁Under ▁McC le ll an , ▁E wing ▁commanded ▁a ▁regiment ▁and ▁then ▁a ▁brig ade ▁in ▁the ▁K ana wh a ▁Division ▁in ▁the ▁IX ▁Corps . ▁In ▁the ▁Battle ▁of ▁South ▁Mountain , ▁he ▁led ▁the ▁assault ▁which ▁drove ▁the ▁enemy ▁from ▁the ▁sum mit ; ▁and ▁at ▁mid night ▁of ▁that ▁day , ▁he ▁received ▁an ▁order ▁placing ▁him ▁in ▁command ▁of ▁the ▁brig ade ▁of ▁Colonel ▁El ia kim ▁P . ▁Sc am mon , ▁who ▁was ▁in ▁temporary ▁command ▁of ▁the ▁K ana wh a ▁division ▁after ▁its ▁commander ▁Major ▁General ▁Jacob ▁D . ▁C ox ▁had ▁been ▁elev ated ▁to ▁command ▁of ▁the ▁IX ▁Corps , ▁replacing ▁the ▁fallen ▁Major ▁General ▁J esse ▁Lee ▁Ren o ▁who ▁was ▁killed ▁earlier ▁that ▁day . ▁At ▁Anti et am ▁his ▁brig ade ▁was ▁placed ▁upon ▁the ▁extreme ▁left ▁of ▁the ▁army , ▁where , ▁according ▁to ▁the ▁report ▁of ▁the ▁commander ▁of ▁the ▁left ▁wing , ▁General ▁Am bro se ▁Burn side , ▁" by ▁a ▁brilliant ▁change ▁of ▁front ▁he ▁saved ▁the ▁left ▁from ▁being ▁completely ▁driven ▁in ." ▁ ▁After ▁Anti et am , ▁E wing ▁was ▁placed ▁on ▁sick ▁leave ▁because ▁of ▁chron ic ▁d ys ent ery , ▁and ▁was ▁promoted ▁to ▁Brig ad ier ▁General ▁on ▁November ▁ 2 9 , ▁ 1 8 6 2 . ▁He ▁transferred ▁West ▁and ▁served ▁throughout ▁the ▁campaign ▁before