The commissioning of Dreadnought set the navies of the world to zero, or close enough. The reasons for this remain unclear. Dreadnought represented no great technical revolution; she was simply larger, faster, and more heavily armed than any predecessor. The capacity to build a dreadnought type battleship was easily within the capabilities of any nation that could construct large armored vessels. Accordingly, the French, Russian, US, and German navies immediately began construction on their own dreadnoughts (the US South Carolina class, indeed, had been designed before Dreadnought). Those countries without the capacity to build large armored ships simply bought them from others, most often Great Britain. This group included Brazil, which ordered three battleships from British yards in the years before the First World War. Minas Gerais and Sao Paulo were delivered to Brazil in 1910, but the third ship, to be named Rio De Janiero, had another path.
Minas Gerais and Sao Paulo were very similar to Dreadnought in appearance and design, although they were slightly larger and carried 12 12″ guns, rather than the ten of Dreadnought. When presented to Brazil, the two ships were probably the most powerful in the world. They were certainly superior to the latest class of US battleships, although the US Navy commissioned four dreadnoughts in 1910 and two each in 1911 and 1912. The purchase of these ships spurred a minor naval race between Brazil and its Southern Cone neighbors, as Argentina ordered two ships from the United States in 1910, and Chile one from the UK in 1912 (although the Chilean battleship, Almirante Latorre, served in the Royal Navy as Canada for four years before delivery).
Other than Canada, none of these ships ever saw combat. For the Southern Cone navies (as well as for some others) battleships served no meaningful military purpose. Any war between the three states would be decided on land. The possession of a pair of dreadnoughts, even if the ships were state of the art, would not long dissuade a major naval power from intervention; as noted above, the US possessed eight such ships by 1912, would commission another eight by 1918, another five by 1923. At the Battle of Jutland, the Grand Fleet deployed thirty seven dreadnoughts and the High Seas Fleet twenty one. Sao Paulo and her kin were symbols, meant to indicate to foreign and domestic audiences that Brazil was a modern, powerful player on the world stage. In 1910, with The Influence of Sea Power on History being read by one and all, being modern meant possessing a dreadnought.
It did not, however, mean maintaining a dreadnought. Brazil has pursued a more active world presence that its neighbors in South America, and participated on the Allied side in both World War I and World War II. Upon Brazil’s declaration of war in 1917, it was thought sensible to deploy Minas Gerais and Sao Paulo with the Grand Fleet. Sadly, the two ships were in such poor condition that they had to be refit in order to be made battleworthy. The refits lasted nearly two years, extending well after the end of the war. The rest of the Brazilian Navy made a genunine contribution to the war effort by patrolling for U-boats in the South Atlantic.
During the interwar period the Brazilian Navy decided to modernize both of the ships. Between 1931 and 1935 Minas Gerais was extensively reconstructed. Sao Paulo, however, was in such bad shape that modernization was pointless. She served her last twenty years as a stationary defense ship, until being sold for scrap in 1951. In a storm off the Azores, Sao Paulo broke her tow line and disappeared. No evidence of the wreck was ever found.