He ended his journey emaciated at three-quarters of the weight he started with on the watercourse now found in atlases as the Roosevelt River. Eventually Colonel Roosevelt was downed by injury and fever. The beefy former president must have embodied some prime cuts for the cannibals as he sat in his canoe. There were poisonous plants, malevolent insect swarms and native warriors, ever present and never seen.

There were pit vipers, piranhas and tiny fish that attack where a man is most vulnerable. With heavy, useless equipment and inappropriate provisions, the Roosevelt-Rondon Expedition ventured into the luxuriant wilderness where every life form threatened. (It’s an exploit that standard TR biographies generally treat lightly, if at all). And so, with devoted son Kermit and truly intrepid Brazilian co-commander Cândido Rondon, along with a band of hardy recruits, the party plunged into the fierce, fecund jungle and its unknown dangers. When the opportunity came to change a planned route to follow the uncharted course of the ominously named River of Doubt, the former chief executive seized it eagerly. A confluence of circumstances, including a South American speaking tour and the eagerness of others to investigate the Amazonian headwaters, brought Teddy, aged 55 and still bold and plucky, to Brazil, then largely unmapped and unknown. In an admirable debut, historian Millard records Theodore Roosevelt’s exploration of a hitherto uncharted river in the heart of the Mato Grosso.

president, failing re-election, has an adventure that nearly kills him.

The river of doubt by candice millard