"Dr. Livingstone, I presume?" So goes the signature introduction of New York Herald star journalist Henry Morton Stanley to renowned explorer Dr. David Livingstone, who had been missing for six years in the wilds of Africa. Into Africa ushers us into the meeting of these remarkable men. In 1866, when Livingstone journeyed into the heart of the African continent in search of the Nile's source, the land was rough, unknown to Europeans, and inhabited by man-eating tribes.

In 1541, the brutal conquistador Gonzalo Pizarro and his well-born lieutenant Francisco Orellana set off from Quito in search of La Canela, South America's rumored Land of Cinnamon, and the fabled El Dorado, "the golden man". Driving an enormous retinue of mercenaries, enslaved natives, horses, hunting dogs, and other animals across the Andes, they watched their proud expedition begin to disintegrate even before they descended into the nightmarish jungle, following the course of a powerful river.

In the late 19th century, demand for fur was in sharp decline. This could have spelled economic disaster for the venerable Hudson's Bay Company. But an idea emerged in political and business circles in Ottawa and Montreal to connect the disparate British colonies into a single entity that would stretch from the Atlantic to the Pacific. With over 3,000 kilometers of track, much of it driven through wildly inhospitable terrain, the CPR would be the longest railroad in the world and the most difficult to build. Its construction was the defining event of its era.

The Hudson’s Bay Company started out small in 1670, trading practical manufactured goods for furs with the indigenous inhabitants of inland subarctic Canada. Controlled by a handful of English aristocrats, it expanded into a powerful political force that ruled the lives of many thousands of people - from the lowlands south and west of Hudson Bay, to the tundra, the great plains, the Rocky Mountains, and the Pacific Northwest.

In 1519 Magellan and his fleet of five ships set sail from Seville, Spain, to discover a water route to the fabled Spice Islands in Indonesia, where the most sought-after commodities (cloves, pepper, and nutmeg) flourished. Three years later, a handful of survivors returned with an abundance of spices from their intended destination, but with just one ship carrying 18 emaciated men. During their remarkable voyage around the world the crew endured starvation, disease, mutiny, and torture. Many men died, including Magellan, who was violently killed in a fierce battle.

On January 28, 1742, a ramshackle vessel of patched-together wood and cloth washed up on the coast of Brazil. Inside were thirty emaciated men, barely alive, and they had an extraordinary tale to tell. They were survivors of His Majesty’s Ship the Wager, a British vessel that had left England in 1740 on a secret mission during an imperial war with Spain. While the Wager had been chasing a Spanish treasure-filled galleon known as “the prize of all the oceans,” it had wrecked on a desolate island off the coast of Patagonia.

In August 1897, the young Belgian commandant Adrien de Gerlache set sail for a three-year expedition aboard the good ship Belgica with dreams of glory. His destination was the uncharted end of the earth: the icy continent of Antarctica. But de Gerlache’s plans to be first to the magnetic South Pole would swiftly go awry. After a series of costly setbacks, the commandant faced two bad options: turn back in defeat and spare his men the devastating Antarctic winter, or recklessly chase fame by sailing deeper into the freezing waters.

In 1528, a mission set out from Spain to colonize Florida. But the expedition went horribly wrong: Delayed by a hurricane, knocked off course by a colossal error of navigation, and ultimately doomed by a disastrous decision to separate the men from their ships, the mission quickly became a desperate journey of survival. Of the 300 men who had embarked on the journey, only four survived - three Spaniards and an African slave.

In 1803, President Thomas Jefferson selected his personal secretary, Captain Meriwether Lewis, to lead a voyage up the Missouri River, across the forbidding Rockies, and - by way of the Snake and the Columbia rivers - down to the Pacific Ocean. Lewis and his partner, Captain William Clark, endured incredible hardships and witnessed astounding sights. With great perseverance, they worked their way into an unexplored West. When they returned two years later, they had long since been given up for dead.

Traditionally, Americans learned in school that the ancestors of the people who inhabited the Western Hemisphere at the time of Columbus' landing had crossed the Bering Strait 12,000 years ago; existed mainly in small nomadic bands; and lived so lightly on the land that the Americas were, for all practical purposes, still a vast wilderness. But as Charles C. Mann now makes clear, archaeologists and anthropologists have spent the last 30 years proving these and many other long-held assumptions wrong.