The author takes his readers on a journey of discovery around the post-Columbian globe. The story begins in Jamestown, a British colony in what is now the US state of Virginia, where a Dutch pirate ship turned up in August 1619 with nearly two dozen black slaves onboard, captured when the pirates attacked a Portuguese slave ship. As it was harvest time, the Jamestown colonists seized the opportunity to buy the slaves.
That purchase set the seal on slavery in America. But what the Virginia tobacco farmers didn't realize was that by buying the labor of slaves from Africa, they also acquired the disease these Africans carried in their blood. Plasmodium falciparum, a parasite that causes malaria, now gained a foothold in North America. Attacks of this fever were a high price the colonial farmers paid for their exploitation of African slaves.
Mann argues that this had far-reaching consequences. In the north, where the cold climate made it hard for malaria-carrying mosquitoes to survive, he says, European immigrants made for an inexpensive alternative to African slaves. In the American South, however, Caucasians fared much more poorly in the mosquito-infested cotton and tobacco fields. Only the slaves from Africa brought with them a certain degree of resistance.
In this way, Mann argues, malaria cemented the system of slavery in the American South. White plantation owners withdrew to their mansions in breezy locations that offered partial protection from the disease, leaving black slaves to toil in the fields.
When he first saw a map of malaria's range, Mann says it was as if the scales had fallen from my eyes. That range extends almost precisely to the Mason-Dixon Line, along which the American Civil War broke out in 1861, between the slave-holding states of the South and the Union soldiers of the North.
The "Columbian Exchange" -- as historians call this transcontinental exchange of humans, animals, germs and plants -- affected more than just the Americas. In China, for example, the new era began when sailors reported the sudden appearance of Europeans in the Philippines in 1570. The astonishing thing about this was that they had come across the ocean from the east.
Until this point, China had shown little interest in Europe, in the belief that its inhabitants had little to offer China's blooming civilization. This time, though, the new arrivals brought something from America that electrified China -- silver.
This precious metal was the most important form of currency, in which all business was transacted, during the Ming Dynasty. Thus, in the eyes of the Chinese, the galleons from South America arrived loaded with nothing less than pure money.
No wonder, then, that a brisk trans-Pacific trade quickly developed. To the chagrin of the Spanish crown, much of the silver mined in the Andes was delivered not to Spain but to far-away China. In exchange, silk, porcelain and other Chinese luxury goods made their way eastward toward Mexico.
The Silver Rush
Mann uses the example of two 17th-century boomtowns to illustrate the change that gripped the globe during this period. Showy, aggressive and teeming with energy, these cities represented the spirit of a new era.