José Plácido de Castro led a surprise uprising in Xapuri, marking the start of the Acre War's final phase. This movement was spearheaded by Brazilian rubber tappers resisting Bolivian administration during the regional rubber boom. The successful seizure of the local garrison ignited a broader military campaign across the territory. Following months of intense guerrilla warfare, Acrean forces achieved a decisive victory at Puerto Alonso in early 1903. This military pressure paved the way for the Treaty of Petrópolis, which formally transferred the region to Brazil.
