no ▁relation ). ▁In ▁this ▁role , ▁John ston ▁participated ▁in ▁actions ▁against ▁the ▁Si oux ▁in ▁the ▁Wy oming ▁Territ ory ▁and ▁in ▁the ▁violence ▁over ▁sla very ▁in ▁the ▁future ▁state , ▁known ▁as ▁Ble eding ▁Kansas . ▁He ▁developed ▁a ▁ment or ▁relationship ▁and ▁close ▁friendship ▁with ▁one ▁of ▁his ▁junior ▁officers , ▁Capt . ▁George ▁B . ▁McC le ll an . ▁Later ▁McC le ll an ▁faced ▁him ▁from ▁the ▁Union ▁Army . ▁ ▁In ▁the ▁fall ▁of ▁ 1 8 5 6 , ▁John ston ▁was ▁transferred ▁to ▁a ▁dep ot ▁for ▁new ▁rec ruits ▁at ▁Jefferson ▁Bar ra cks , ▁Missouri . ▁In ▁ 1 8 5 7 ▁he ▁led ▁surve ying ▁exped itions ▁to ▁determine ▁the ▁Kansas ▁border . ▁Later ▁that ▁year , ▁Davis ▁was ▁replaced ▁as ▁Secretary ▁of ▁War ▁by ▁John ▁B . ▁F loyd , ▁a ▁native ▁of ▁Ab ing don ▁and ▁a ▁cousin ▁of ▁John ston ' s ▁by ▁marriage . ▁He ▁had ▁been ▁a ▁former ▁guard ian ▁of ▁Pr eston ▁John ston . ▁F loyd ▁made ▁John ston ▁a ▁bre vet ▁colon el ▁for ▁his ▁actions ▁at ▁Cer ro ▁G ordo , ▁a ▁promotion ▁that ▁caused ▁gr umb ling ▁within ▁the ▁Army ▁about ▁favor it ism . ▁In ▁ 1 8 5 9 , ▁President ▁James ▁Buch an an ▁named ▁John ston ' s ▁brother - in - law , ▁Robert ▁Mc L ane , ▁as ▁minister ▁to ▁Mexico , ▁and ▁John ston ▁accompanied ▁him ▁on ▁a ▁journey ▁to ▁visit ▁Ben