 Ramba uchiverenga ndima iyi - Muna 1845, Bliss akapinda muuto reUnited States raipinda muRepublic of Texas, risati rabatwa. Pakati paApril 1846 naNovember 1847, akatora rutivi muHondo yeMexico, kusanganisira kurwa muhondo dzePalo Alto, Resaca de la Palma uye Buena Vista. Akakwidziridzwa kuva Major muna May 1846, uye akakwidziridzwa kuva Lieutenant Colonel muna February 1847 nokuda kwebasa rakashinga uye rakakodzera. 