ritt enden ▁would ▁advance ▁against ▁the ▁city ▁from ▁the ▁west , ▁the ▁XIV ▁Corps ▁under ▁Maj . ▁Gen . ▁George ▁H . ▁Thomas ▁would ▁cross ▁over ▁Look out ▁Mountain ▁ 2 0 ▁miles ▁south ▁of ▁the ▁city , ▁while ▁the ▁XX ▁Corps ▁under ▁Maj . ▁Gen . ▁Alexander ▁M . ▁McC ook ▁and ▁the ▁Caval ry ▁Corps ▁under ▁Maj . ▁Gen . ▁David ▁S . ▁Stanley ▁would ▁advance ▁even ▁farther ▁to ▁the ▁sout heast ▁toward ▁B rag g ' s ▁rail road ▁supply ▁line ▁leading ▁from ▁Atlanta . ▁If ▁executed ▁correctly , ▁this ▁plan ▁would ▁cause ▁B rag g ▁to ▁ev acu ate ▁Ch att ano oga ▁or ▁be ▁tra pped ▁in ▁the ▁city ▁without ▁supplies . ▁ ▁Cross ing ▁the ▁Tennessee ▁Rose cr ans ▁ordered ▁his ▁army ▁to ▁move ▁on ▁August ▁ 1 6 . ▁The ▁difficult ▁road ▁conditions ▁meant ▁a ▁full ▁week ▁passed ▁before ▁they ▁reached ▁the ▁Tennessee ▁River ▁Valley . ▁They ▁enc amp ed ▁while ▁engine ers ▁made ▁prepar ations ▁for ▁crossing ▁the ▁river . ▁Meanwhile , ▁Rose cr ans ' s ▁de ception ▁plan ▁was ▁under way . ▁Col . ▁John ▁T . ▁W ilder ▁of ▁the ▁XIV ▁Corps ▁moved ▁his ▁mounted ▁inf antry ▁brig ade ▁( the ▁Light ning ▁Brigade , ▁which ▁first ▁saw ▁prom in ence ▁at ▁Ho over ' s ▁G ap ) ▁to ▁the ▁north ▁of ▁Ch att ano oga . ▁His ▁men ▁p ounded ▁on ▁tub s ▁and ▁saw ed ▁bo ards , ▁sending ▁pieces ▁of ▁wood ▁down stream , ▁to ▁make ▁the ▁Confeder