Through the Brazilian Wilderness is Theodore Roosevelt's biographical account of hunting, camping and "zoogeographical reconnaissance" with his son Kermit in the Brazilian jungle.

Following his presidency, he set out on an expedition to explore and map unknown regions of Paraguay and Brazil on the 950-mile River of Doubt, a previously unexplored tributary of the Amazon River. For six weeks Roosevelt and his party paddled and carried canoes down the 950-mile river now called the Rio Roosevelt. Men died, boats were lost, food became scarce, fever borne by insects sickened many in the party which led to Roosevelt's death five years later.

The expedition collected thousands of species of birds and mammals. Roosevelt admired those who lived life with passion and for what he called "the Great Adventure." The story of his expedition, as chronicled in Through the Brazilian Wilderness, tells one of Roosevelt's last great.

Theodore "Teddy" Roosevelt was the 26th President of the United States. He is noted for his energetic personality, range of interests and achievements, leadership of the Progressive Movement, and his "cowboy" image and robust masculinity. He was a leader of the Republican Party and founder of the short-lived Progressive ("Bull Moose") Party of 1912. Roosevelt's achievements as a naturalist, explorer, hunter, author, and soldier are as much a part of his fame as any office he held as a politician.