Latin Fronts
Following their defeat at Paranhos the Paraguayans with drew to their new defensive lines at Curuguaty with the Brazilians in quick pursuit. On August 2 the Battle of Curuguaty began as Brazilian forces began assaulting the Paraguayan lines. The Battle of Curuguaty would last until August 9 when the weight of Brazilian numbers would force the enemy from their trenches. By mid September Marshal César and his army had made it halfway to the Paraguayan capital and Bolivian forces had captured Conception. Paraguay had finally gotten some assistance in the form of 70,000 Argentine forces. On September 17 the Battle of San Estanisiao began and for once Brazil didn't have numerical superiority.
Following the Battle of Salto Brazil was exhausted and while artillery duels continued across the Uruguay River the Brazilian's held still for nearly a month. Finally, after being reinforced to nearly 300,000, Marshal Carneiro ordered his army to attack beginning the Battle of the Uruguay. The lull however had also allowed Argentina to move up new troops and, along with the remaining Uruguayans, numbered over 250,000. The Battle of the Uruguay would go on for over two months and end up being stretched across 30 miles before it would end.
As Marshal Carneiro prepared for the attack across the Uruguay, the second line of Brazilian's were preparing another offensive on the Uruguayan capital Montevideo. However instead of attacking again at Tacuarembo, where the majority of Uruguayan troops were deployed, a new invasion was a second invasion occurred on September 1. At 4am General José Jardim invaded eastern Uruguay with 80,000 men. The Uruguayans had very few men available to confront this new threat and the Brazilian's moved quickly easily defeating the 20,000 strong garrison at the Battle of Melo and another at the Battle of Treinta y Tres. By the end of September nearly all of uruguay was under Brazilian control and only 80,000 Uruguayan troops and militia stood in between them and Montevideo. As the Battle of Montevideo began on October 3 however, these outnumbered, outgunned, and outtrained troops would make Brazil pay for every block, street, and house thy captured in blood.
The Ecuadorian Front opened up on July 1 as Peruvian and Colombian artillery opened up on on the Ecuadorians. Since becoming allied with Brazil and with it the Entente, Ecuador had been receiving significant amounts of arms from the US and France as well as trainers from these nations as well. By the time war began Ecuador had a highly professional and modern army second only to Brazil on the continent. What they couldn't import however was a larger population and though they had a technological advantage over Peru and Colombia they were outnumbered 3-1 and was forced to fight on two fronts.
After three hours of bombardment Colombian forces would attack the Ecuadorians in waves at their fortifications at Tulcán. The Battle of Tulcán lasted on thirty hours before the city fell to the Colombians. Using the sheer force of numbers Colombia advanced forward and by August all of the Carchi and Sucumbíos regions were under their control however their march down the coast was halted by fierce Ecuadorian resistance on July 25 at the Battle of Rosa Zárate. Here Ecuador would hold the Colombians at bay for over a month, not withdrawing until September 7.
Ecuador wasn't Colombia's only front to fight on. On July 4 just after delivering its declaration Colombian forces invaded Panama with over 100,000 men advancing. To combat this the US had only 30,000 men under Major General Frederick Funston in the area and available to fight. The narrow stretch of the isthmus however made this less of a problem and General Funston would use this terrain to their advantage. The Battle of the Darién Gap would go on for forty-four days as the Colombians threw wave after wave of troops against the Americans slowly driving them back. By mid August however the Colombian Army was exhausted and on August 17 the battle came to an end with the line only forty-five miles into Panama.
On Ecuador's southern front the Peruvians were attacking as well. In just two days they would defeat Ecuador in the Battle of the Chinchipe and began their invasion of Ecuador. The Peruvians captured territory in eastern Ecuador fairly quickly however, closer to the coast Ecuador would make a stand on July 17 at the Battle of Zamora. It would take twenty-nine days before Peru would finally wrest the city from Ecuador. Exhausted the Peruvians wouldn't move again for a month.
While advancing on Ecuador, Peru itself would be under attack and invaded on its southern borders. On July 8 45,000 Bolivian troops invaded Peru. This was seen as a lesser front for both sides so the numbers that were engaged here were reasonably small. Peru had only 37,000 men in the area and the two armies met one another on July 21 near Azángaro. The Battle of Azángaro would last for three days and more resemble a battle from the previous century than a new modern one. The Bolivian's would win the day and capture the city with Peru withdrawing to Macusani. A month later Bolivia attacked again with more forces at the Battle of Macusani. Peru had moved in more troops as well however and here the fighting would bog down and continue off and on for most of September.
The Chilean border would be the main theater for Peru, and Chile, to fight on. On July 6 General Adolfo Holley attacked Tacna in southern Peru with 185,000 men. Peru was anticipating a Chilean attack however and 110,000 Peruvians were on the border in well made fortifications. The Battle of Tacna started off the war in a massive blood lust. For almost two full months the Battle of Tacna raged with thousands being slaughtered. On September 2 the ruins of Tacna would finally fall to Holley. However the massive of casualties had exhausting the Chileans and couldn't pursue.
Though Chile and Argentina had a very long border the mountainous terrain would see only limited action. In Patagonia however 40,000 Chilean troops under General Estanislao del Canto invaded southern Argentina on July 26. The Argentine's didn't have many troops to spare to combat the Chileans and on August 17 lost the Battle of Puerto Deseado to Chile. Logistics in the Patagonian Front were terrible and Chile didn't have a whole lot of extra supplies to send to this backwater theater so after this initial campaign General del Canto was forced to halt more operations for the time being.
The borders between Brazil, Peru, and Colombia were long. These regions however were sparsely populated and would be considered a backwater theater from both sides with far more important fronts to be fought there would rarely be more than 75,000 troops in total here and while the fighting was usually on Brazilian territory, Peru and Colombia knew that they wouldn't be the ones to knock out Brazil.