The Battle of Acosta Ñu occurred during a pivotal phase of the Paraguayan War, which involved a coalition of Brazil, Argentina, and Uruguay against Paraguay. In an effort to resist the advancing Brazilian forces, Paraguay mobilized a battalion largely made up of young boys and children, many of whom had been conscripted or volunteered due to the dire circumstances their country faced. On this day, the Paraguayan troops, under the command of General José E. Díaz, found themselves ill-prepared against a well-trained Brazilian army known for their tactical efficiency and combat experience.

As the battle progressed in the village of Acosta Ñu, the young Paraguayan soldiers quickly became overpowered by the Brazilian might. The lack of experience and military training rendered them vulnerable, and the engagement led to a brutal massacre. Reports indicate that many of the child soldiers, despite being armed, fled in despair, leaving their comrades to face the onslaught unassisted. The overwhelming firepower and strategic maneuvering of the Brazilian troops culminated in a devastating defeat for the Paraguayan side.

Following this confrontation, numerous accounts emerged highlighting the horrors faced by these young recruits. The event stands out not only for the tragic loss of life but also for the brutal realities of war and the involvement of minors in such violent conflicts. This battle remains a poignant example of the lengths nations resort to in times of desperation, as well as the heartbreaking consequences of war on a society's youth, who were caught in the throes of a national crisis.