Rubuta ci gaba don wannan sakin layi - A ranar 8 ga Mayu, 1846, Zachary Taylor da sojoji 2,400 sun isa don sauƙaƙe sansanin. Koyaya, Janar Arista ya hanzarta arewa tare da rundunar 3,400 kuma ya tsayar da shi game da arewacin Kogin Rio Grande, kusa da Brownsville na zamani, Texas. Sojojin Amurka sun yi amfani da "makamai masu tashi sama", kalmarsu don bindigogin doki, bindigogi masu sauƙi masu motsi waɗanda aka ɗora a kan karusan dawakai tare da duka ma'aikatan da ke hawa dawakai zuwa yaƙi. Gidan wuta mai sauri da kuma goyon bayan wuta mai mahimmanci yana da mummunar tasiri a kan sojojin Mexico. Ya bambanta da "makamai masu tashi sama" na Amurkawa, bindigogin Mexico a Yaƙin Palo Alto
yana da gunpowder mai ƙarancin inganci wanda aka harba a saurin jinkirin da ya isa ya sa ya yiwu ga sojojin Amurka su guji harbe-harben bindiga. 'Yan Mexico sun amsa tare da dakarun doki da kuma bindigogin kansu. Jirgin sama na Amurka ya ɗan rage ƙarfin ɓangaren Mexica, kuma yana neman ƙasa mafi amfani a gare su, Mexica sun koma baya zuwa gefen wani kogi mai bushe "resaca" a cikin dare kuma sun shirya don yaƙi na gaba. Ya samar da wani halitta fortification, amma a lokacin da baya, Mexican sojojin da aka tarwatsa, yin sadarwa wuya.