Rubuta ci gaba ga wannan sakin layi - A 1826 ya sake shiga aikin soja, a wannan lokacin a cikin Cisplatine War. A cikin yakin basasa na Argentina, ya shiga bangaren Unitarian, a karkashin jagorancin Janar José María Paz, kuma ya yi yaƙi a La Tablada da sojojin tarayya. Bayan dogon lokaci a gudun hijira, ya koma kasar bayan faduwar mulkin Rosas
, kuma ya yi aiki a matsayin Sanata na lardin San Luis. A shekara ta 1856, an nada shi kwamandan rundunar sojin kan iyaka, kuma a shekara ta 1859 an zabe shi Gwamnan San Luis, kuma ya yi yaƙi a yakin Cepeda a wannan shekarar.