South America was an Earth continent.
The Second Doctor, John and Gillian visited South America and helped a native village defend themselves from an enemy tribe. (COMIC: The TARDIS Worshippers)
The black orchid flower was only found in South America. (TV: Black Orchid)
In 1911, the Forge harvested vampire DNA in South America. The DNA was used in Project: Twilight. (PROSE: Project: Valhalla)
In the late 20th century, amidst growing tensions between Russia and China, fighting broke out in South America and southern Asia before Sir Reginald Styles was able to negotiate peace, cooling the crisis and preventing World War Three, with the Third Doctor preventing an alternate timeline where Styles was assassinated and war did indeed come to pass. (TV: Day of the Daleks)
In Pete's World in 2004, the South American state reported that 265,000 people had gone missing, implied to be Cybermen experiments. (WC: Tardisode 5)
Following the plague sent by the Daleks during their 22nd century invasion of Earth a majority of the population of South America died before a cure could be found. (TV: The Dalek Invasion of Earth)
One South American jungle was home to a mushroom known as the Great Power. The Daleks travelled to this jungle to obtain it, where they were defeated by the First Doctor and the Chief Voord. (PROSE: Doctor Who and the Daleks)