Before the start of the war, the land of the current states of New Mexico and Arizona was part of the New Mexico Territory and the Gadsden Purchase, which ran parallel to William Walker's Republics of "Lower California" and "Sonora". As early as 1856, the territorial government in Santa Fe had raised concerns about being able to effectively govern the southern part of the territory. It was separated from the rest by the Jornada del Muerto, a difficult stretch of desert.