After 1912, Theodore left politics to embark on a yearlong trek in Brazil. Roosevelt wanted to map out a river to see where it connected to the Amazon. The river had been named the Rio de Dúvida (River of Doubt) due to the fact that no one really knew where it began or ended in accordance with the Amazon River. The journey itself was not only long and arduous, but relatively dangerous with the heat, diseases such as malaria and numerous others, and the presence of predatory animals. Most of the explorers on the team were sick during the entire expedition. Their dug-out canoes were no match for some of the more treacherous parts of the river; some of their canoes were lost, causing them to spend days building new ones. The name was changed to the Rio de Roosevelt after Teddy trailed the entire river and found its origin. Because some didn’t believe him, other explorers had to verify his discovery by exploring the river themselves, but since Roosevelt had pretty much done the job for them, it was a much easier task for them.