In 1758 Swedish naturalist Carl Linnaeus was able to describe six of the species of deer we know today. Five, of these, perhaps unsurprisingly, were the five species native to Europe. What may be more surprising is that the odd one out isn't the widespread white-tailed deer, or even one of the Asian species, but one from South America. (As an aside, he also identified two species of what he thought were deer living in Africa. One may not even be real, and if it ever was, was probably a misidentified antelope. The other is very definitely real, but is no longer considered to be a 'deer').
That one exception is what we now call the Pampas deer (Ozotoceros bezoarticus). These live, or at least used to, across much of central South America from central Brazil to northern Argentina. Today, they are found primarily in scattered patches of land across the region, although their numbers are just high enough in total to avoid being formally listed as a threatened species (although the same is not true of all the subspecies). The main reason for this is that their preferred habitat, as their common name indicates, is open grassland... and most of that has been converted into farmland, with some estimates suggesting that as little as 1% of the original habitat survives today, as compared with the late 19th century.