Pedzisa mutsara unotevera: Muna 1845, Bliss akapinda mubasa rechiuto reUnited States rokutora Republic of Texas, isati yabatanidzwa. Pakati paApril 1846 naNovember 1847, akatora chikamu muHondo yeMexico, kusanganisira kurwa muhondo dze
Palo 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.