 Nyorai kupfuurira kweiyi ndima - Longstreet akabatira nokusiyanisa muHondo yeMexico neAmerica ne8th U.S. Infantry. Akarwa pasi paZachary Taylor semutungamiriri muna Chivabvu 1846 muhondo dzePalo Alto neResaca de la Palma. Akarondedzera hondo mbiri idzi mumashoko ake okuyeuka asi haana kunyora chinhu pamusoro pebasa rake amene madziri. Musi waJune 10, Longstreet akapiwa mutungamiri weKambani A yeEighth Infantry yeWilliam J. Worths Second Division. Akarwazve neuto raTaylor muHondo yeMonterrey muna September 1846. Mukati mehondo yacho, varwi vechiMexico vanenge 200 vakadzinga boka revarwi vokuAmerica. Longstreet, achitungamirira makambani A neB, akatungamirira kurwisa, achiuraya kana kukuvadza inenge hafu yevarwi. Musi waFebruary 23, 1847, akakwidziridzwa kuva lieutenant wokutanga. Mukuru-mukuru Winfield Scott akarayira boka raWorth kuti ribve muuto raTaylor uye pasi pehutungamiri hwake chaihwo kuitira kuti vatore chikamu pakurwisa guta guru reMexico reMexico City. Boka raWorth rakatanga kutumirwa kuLobos Island. Kubva ipapo yakafamba makiromita 289,7 kumaodzanyemba kuguta reVeracruz. Worth akatungamirira hondo yaScott mukufamba kwayo kwepasi nepasi muguta racho, achisvika ikoko pana March 9. Scott akakomba guta racho uye akarirwisa nebhomba nguva dzose. Rakazviisa pasi pana March 29. Mauto eAmerica ipapo akafamba kuchamhembe akananga kuguta guru. MunaAugust, Longstreet akashanda muHondo yeChurubusco, hondo inokosha sezvo U.S. Army yakaswedera pedyo nekutora Mexico City. Mauto e8th Infantry ndiwo chete aiva muboka raWorth akasvika pamadziro eMexico. Longstreet akatakura mureza wehondo pasi pokurwiswa zvikuru nevaMexico. Mauto acho akazviwana ava mumukanza uye aigona kungokwira masvingo eMexico nokumira pamusoro pomumwe nomumwe. Mukurwisana kwakasimba kwakazotevera, vaAmerica vakakunda. Longstreet akagamuchira kukwidziridzwa kwepamutemo kuva kaputeni nokuda kwezviito zvake paChurubusco. 