The war absolutely devastated Paraguay. By the end of the conflict, something like 60% of Paraguay’s population was dead, including 90% of the male population (population counts from this war are notoriously inaccurate; for these numbers I am using Thomas Whigham who did a study of the population in the 1990s). Comparatively, this makes it one of the bloodiest wars per capita ever. The terms of peace took approximately 25% of Paraguayan territory, including some of the prime yerba mate growing farmland. This hampered economic development in the country by basically eliminating the one cash crop that they produced. Worse still, the war negated Paraguay’s (very) modest industrialization, and to this day, the country retains an agricultural economy. This outcome was further cemented as a result of Allied destruction and looting of Asunción when they captured it 1869 and other towns. The soldiers sent large amounts of goods and agricultural products back to markets in their home countries. This also resulted in the loss of their national archives, national library, and other historical memories. Furthermore, the Allies expected Paraguay to pay war reparations, which the country did not finish paying until 1943. Politically, the war resulted in a new government, which was firmly anti-Lopez and which some describe as a puppet of the Allies. The war wrecked the aristocracy of Paraguay which traditionally held the political power, and filling the void after the conflict was a new flock of political parties which vied for power through coups and counter-coups throughout the remainder of the 19th century. Brazil and Argentina supported friendly parties, and Brazil even financed a coup in 1894. Most significantly, the conflict remains something of a tragedy, a deep scar on Paraguay’s psyche which never really healed. Politicians throughout the twentieth century described the war in absolutist terms and related regional power grabs as a continuation of the war. Consequently, it was a watershed moment for Paraguay’s political, economic, and social trajectory and caused a massive shift in regional power away from fractured provinces to strong (and big) nation-states.

It was the exact opposite in Uruguay where the effects of the war were only tangentially felt and almost immediately forgotten. López initiated the conflict in Uruguay’s name, specifically to restore the Blanco Party to power which he saw as integral to the balance of power on the continent. The war, then, became something of a defense of the Colorado Party and the Flores regime that had recently ascended to political domination. Flores, the president (who really was more of a dictator), begrudgingly supplied 1,500 of his best Colorado troops to the effort, most of whom died of disease or were killed in battle. To replace them, they drafted Uruguayan and Argentine gauchos, but they deserted whenever possible since they had no stake in the conflict. To replace the deserters, the Uruguayan officers conscripted Paraguayans who opposed the López government and prisoners of war. Looking at the big picture, Uruguay was still not yet a unified country. From 1868-1872, there was another civil war which resulted in the first significant sharing of power between the Colorados and the Blancos. During the conflict, Flores was assassinated, and his successors had no interest in continuing in the Paraguayan War when they had much more pressing issues to deal with close to home. Thus by the time the army was recalled in 1869, only 150 Uruguayans were on the boat home. Maybe the most significant legacy of the war were outbreaks of disease and inflation that swept through Uruguay in the late 1860s, but even the effects of these were short-lived. So for Uruguay, the war was only a small part of a larger story of national unification that did not have any significant intersection with the Paraguayan War.

Argentina experienced the war differently than both of these countries. Although the conflict benefited many wealthy landowners and businessmen who provided war supplies, the most obvious effect of the war was immediate internal conflict. The war was exceedingly unpopular with the interior provinces, especially the poor gauchos who were drafted to fight. Many provinces were engulfed in significant rebellions sparked by opposition to the war. In fact, more Argentine troops were killed dealing with these uprisings than were actually killed fighting in Paraguay. Loyal governors to Mitre in Buenos Aires struggled to muster the required troops needed at the front, and often, the men they conscripted were ranch hands and gauchos who had no interest fighting in Buenos Aires’ war. Likewise, porteños criticized the war effort, and Mitre rapidly lost his control over the politics of the fragile new country. When López invaded Argentina initially, he probably predicted that Argentina would fall apart into such a civil war. He was right, but Argentina managed to stay together long enough for Brazil to consolidate enough to finish the war virtually by themselves. In 1868, Sarmiento won the election, driving the unpopular Mitre from office. Famously, Sarmiento initiated many reforms that significantly altered Argentina like encouraging education and European immigration. Consequently, Argentina entered into a period of prolonged economic growth driven by immigration and an agro-export economy that wowed the world. In reality though, this growth overcame, as opposed to resulted from, the legacy of the Paraguayan War.