Throughout his life, Theodore Roosevelt overcame personal trials such as life-threatening childhood asthma and the untimely deaths of first his father, and later his mother and wife, by embracing physical exertion and feats of survival in the wilderness. In the realm of politics, nature provided Roosevelt with some of the proudest achievements as president of the United States from 1901 to 1908, with his administration establishing the United States Forest Service and inaugurating hundreds of national monuments, forests, parks, and wildlife preserves. In 1909, Roosevelt weakened the pain of exiting the White House by setting out on an African safari. When he suffered humiliating defeat in his bid for a third term in the presidential election of 1912, Roosevelt once again looked to the outdoors to prove the resilience of his will. This time, with the help of the American Museum of Natural History, he would set his sights on exploring Brazil's Amazon rainforest.

Much like the United States, the Brazilian state's territorial claims had historically reached far beyond the regions of settlement of its population. In 1912, the Amazon region, densely forested and populated by untold numbers of Indigenous peoples, had proven almost impenetrable to modern methods of transportation and communication. Cândido Mariano da Silva Rondon was one of the few along Brazil's Atlantic coast who possessed the bravery and knowledge required to navigate the complex geographical and social contours of Brazil's unsettled western territories. Adhering to the motto "die, if necessary, but do not kill" ("morrer se preciso for, matar nunca" in Portuguese), Rondon dedicated his life to balancing the expanding reach of the Brazilian state into the Amazon region with the minimization of harm on its Indigenous inhabitants. After years helping construct telegraph lines in the area, in 1910 Rondon was named the director of the newly-founded Indian Protection Service (Serviço de Proteção ao Índio in Portuguese). Upon receiving word of Theodore Roosevelt's desires to explore the Amazon, Brazil's Ambassador to the United States Domício da Gama had but one choice for the expedition's Brazilian guide. 

On October 4, 1913 Theodore Roosevelt departed from New York along with his son Kermit and a team of naturalists including George Kruck Cherrie and Leo E. Miller. Arriving at Rio de Janeiro several weeks later, Roosevelt met with Brazil's Minister of Foreign Affairs Lauro Müller, who proposed that Roosevelt alter the route of his trip in order to explore the practically unknown River of Doubt (Rio da Dúvida in Portuguese). While shocking those at the American Museum of Natural History who had believed they were sponsoring a much safer expedition for the ex-president, Roosevelt and every member of his team agreed to the drastic change of plans. What ensued was a harrowing journey that led to the death of several members of the expedition and left the ex-president incapacitated for the latter part of the four-month-long journey. Saved from disaster by an encounter with rubber-tappers at the river's confluence with the Aripuanã on April 15, 1914, the Roosevelt-Rondon Expedition ended with widely mixed results: in honor of the expedition, the river was renamed the Rio Roosevelt in 1914; brought within days of death, Theodore Roosevelt's health never seemed to recover, until he passed away in 1919; for Cândido Rondon, who would live to the age of 92, the Roosevelt-Rondon Expedition represented yet another in a long list of accomplishments that have made him one of Brazil's most cherished national figures.

Key events

• Roosevelt-Rondon Scientific Expedition (1913-1914)

Key figures

• Rondon, Cândido Mariano da Silva, 1865-1958.
• Roosevelt, Kermit, 1916-2000
• Roosevelt, Theodore, 1858-1919

Key groups 

• American Museum of Natural History
• Brazil. Comissão de Linhas Telegráficas Estratégicas de Mato Grosso ao Amazonas

Key places 

• Amazon River Valley
• Roosevelt River (Brazil) 

Key subjects 

• Brazil--Description and travel
• Brazil--Discovery and exploration
• Indians of South America--Brazil--Government relations
• Roosevelt, Theodore, 1858-1919--Travel--Brazil