The
Great American War (
GAW), also known in Argentina and Brazil as the
Second Cisplatine War, was a major conflict in the Western Hemisphere from September 1913 until November 1916. It was fought between two major coalitions: the Axis of Liberty, or Axis Powers, and the
Bloc Sud (Bloc of the South). Fighting took place in separate theaters in North, Central and South America, as well as naval engagements in the central Atlantic, south Pacific, and Caribbean Sea. One of the deadliest wars in history and the deadliest to ever occur in the Americas, it saw over three million soldiers killed and seven million wounded, and over two million civilian casualties, disproportionately in the Confederate States and Chile. Hundreds of thousands more died in its aftermath from various internal conflicts, and it was a factor in the 1918-19 North American influenza's lethality.
The first decade of the 20th century saw increasing tensions in the Americas. The United States, which had in the second half of the 19th century emerged as not only the continent's but the world's preeminent industrial power and was gradually starting to develop a military (especially its blue-water navy) and foreign policy doctrine to emerge as a hemispheric hegemon, was opposed diplomatically by a group of nations led primarily by the Confederate States, which had seceded in a bloody two-year conflict from the USA in 1862. With tensions of both an economic, military and ideological disposition (the Confederacy and Brazil kept chattel slavery and both Brazil and Mexico were conservative Catholic monarchies, while the United States and Argentina were seen as fonts of progressive liberal reformism), a breaking point arrived with the opening of the United States' Nicaragua Canal project in proximity to Mexico and the expiration of trade treaties between the USA and CSA allowing unfettered access to the Mississippi River. The Confederate States seized and sank an American trade vessel after killing several crew members after years of rising tensions and having walked out on a British-sponsored Congress to resolve the outstanding issues just a month before, and anticipating an American attack, the Confederacy elected to pursue a pre-emptive attack on Washington and Baltimore to deal a decapitating blow and end the disputes in their favor unilaterally, launching this offensive on September 9, 1913.
This strategy failed, as did Brazil's hope to knock out rival Argentina - an ally of the United States - in the first months of the war with a combined assault across the Parana and a naval victory in the River Plate. Subsequently, despite Mexico joining the CSA and Chile aligning with Brazil in the Andes, both fronts settled into long stalemates, with the United States turning the tide of the war in early 1914 with the defeat of the Confederates upon the Susquehanna River in Pennsylvania and by bringing Peru and Bolivia into the war with Chile, promising them both
irredenta they had lost in 1879's Saltpeter War. The North American front became quickly typified by brutal trench warfare that was augmented by massive artillery attacks and aerial bombings, but the United States gradually crept closer and closer to major Confederate population and industrial centers. The war in the Southern Cone was less dynamic, with Brazil repeatedly failing to break through Argentine lines on the right bank of the Parana at huge cost of men and materiel, while Chile and Argentina both saw little movement in the Andes.
Naval warfare and blockades proved decisive, with the United States dealing decapitating blows to Chile at Desventuradas (April 1914) and the Confederacy at Hilton Head (May 1915) and Florida Straits (August 1915), essentially ending their ability to receive foreign aid from Europe or harry American and Argentinean shipping further. Chile collapsed in early 1915 and exited the war via the harsh peace of the Treaty of Lima after seeing several ports seized by the Axis, leaving Argentina in position to focus exclusively on Brazil; while their attempted counter-offensive in mid-1915 failed, Brazil's soldiers mutinied across the front and the South American front concluded with the Peace of Asuncion in February 1916. Mexico, destabilized internally and seeing incursions across its north by the United States in tandem with several peasant rebellions, exited the war in October of 1915 once it was clear that the tide had been definitively turned after a putsch staged by the head of its Army, thus leaving the Confederacy to fight on alone for the last year of the war.
The Confederate States in 1916 saw an essential collapse of public order and government, with the state of Texas seceding in March of that year and major cities such as Richmond and Atlanta falling over the summer. A major offensive through Georgia in the early autumn broke the country's back entirely, in tandem with huge slave revolts and mass starvation as the harvest failed, and after an abortive putsch in the new capital of Charlotte plunged its government into chaos in the last days of the war, the Confederate States agreed to an armistice on November 11, 1916, still celebrated as Victory Day in the United States as one of the most important federal holidays.
While treaties such as Coronado (US-Mexico) or Asuncion (Argentina-Brazil) were fairly light, the Treaty of Mount Vernon imposed a harsh peace on the Confederacy, which was stripped of several key pieces of territory, had major impositions placed on its economic and military rights, and most prominently demanded the total abolition of slavery as a condition of peace. The end of the war formalized new states such as Sequoyah or Texas and cemented the United States as the hegemon of the hemisphere; however, the lopsided peace triggered massive instability across the Americas not only in the immediate postwar years but for decades to come, particularly in South America where both Argentina and Brazil took the view that they had fought to a draw, and USA-CSA relations would be defined by Confederate resentment towards their northern neighbor for most of the rest of the 20th century.
