issance ▁prior ▁to ▁the ▁Battle ▁of ▁Cer ro ▁G ordo . ▁He ▁was ▁appointed ▁a ▁bre vet ▁lieutenant ▁colon el ▁for ▁his ▁actions ▁at ▁Cer ro ▁G ordo . ▁After ▁recover ing ▁in ▁a ▁field ▁hospital , ▁he ▁rejo ined ▁the ▁army ▁at ▁P ue bla . ▁During ▁the ▁advance ▁toward ▁Mexico ▁City , ▁he ▁was ▁second ▁in ▁command ▁of ▁the ▁" U . S . ▁Regiment ▁of ▁Vol t ige urs ", ▁a ▁unit ▁composed ▁of ▁light ▁inf antry ▁or ▁sk irm ish ers . ▁He ▁distinguished ▁himself ▁at ▁Con tr eras ▁and ▁Ch ur ub us co , ▁was ▁wounded ▁again ▁at ▁Chap ul te pec , ▁and ▁received ▁two ▁bre vet ▁prom ot ions ▁for ▁the ▁latter ▁two ▁engag ements , ▁ending ▁the ▁war ▁as ▁a ▁bre vet ▁colon el ▁of ▁volunte ers . ▁( After ▁the ▁end ▁of ▁host ilities , ▁he ▁revert ed ▁to ▁his ▁pe ac etime ▁rank ▁of ▁captain ▁in ▁the ▁top ographical ▁engine ers .) ▁Win field ▁Scott ▁remarked ▁humor ously ▁that ▁" John ston ▁is ▁a ▁great ▁soldier , ▁but ▁he ▁had ▁an ▁un fortun ate ▁kn ack ▁of ▁getting ▁himself ▁shot ▁in ▁nearly ▁every ▁eng agement ." ▁John ston ' s ▁greatest ▁an gu ish ▁during ▁the ▁war ▁was ▁the ▁death ▁of ▁his ▁nep hew , ▁Pr eston ▁John ston . ▁When ▁Robert ▁E . ▁Lee ▁informed ▁John ston ▁that ▁Pr eston ▁had ▁been ▁killed ▁by ▁a ▁Mexican ▁art illery ▁shell ▁at ▁Con tr eras , ▁both ▁officers ▁we pt , ▁and ▁John