Ya kasance a kan iyaka, garrison, da aikin injiniya har zuwa 1846, lokacin da ya shiga aikin soja na sabon jihar Texas. Daga bisani, ya yi aiki a lokacin yakin Mexican-American, wanda aka ba shi izini a matsayin kyaftin din da kuma babban jami'in ga jaruntaka a wasu muhimman fadace-fadace ciki har da
Yaƙin Palo Alto da Yaƙin Resaca de la Palma. Ya yi aiki a matsayin shugaban ma'aikatan Major Folliott T. Lally a kan tafiya daga Vera Cruz zuwa Mexico City a 1847. Ya shiga kungiyar Aztec ta 1847 a 1871.