Daily History Challenge · No. 100 · Tuesday 6 October 2026 · Chain
Puzzle No. 100: Chain
The anchor was The Columbian Exchange and the demographic collapse of Indigenous America (1493 CE). Every challenger is listed below with its year.
The anchor
Following Columbus's voyages, sustained Atlantic contact set off the Columbian Exchange, a vast two-way transfer of crops, animals, peoples and pathogens between the Old and New Worlds. American staples such as maize, potatoes, cassava, tomatoes, chillies, cacao and tobacco spread across Europe, Africa and Asia, eventually fuelling population growth worldwide, while Europeans brought wheat, sugar, horses, cattle, pigs and other livestock to the Americas, transforming landscapes and Indigenous societies. The most devastating transfers were biological: Eurasian diseases including smallpox, measles, influenza and typhus, to which Indigenous Americans had no immunity, swept through the hemisphere in repeated epidemics. Across the sixteenth and seventeenth centuries roughly 90 percent of the pre-contact population is estimated to have perished, among the largest demographic catastrophes in recorded history; epidemics such as the cocoliztli outbreaks in Mexico killed millions. This collapse facilitated European conquest, drove the importation of enslaved Africans to replace lost labour, and permanently reshaped the world's diets, ecosystems and populations.
The 10 challengers, in order of date
Before The Columbian Exchange and the demographic collapse of Indigenous America
Before The Columbian Exchange and the demographic collapse of Indigenous America
Before The Columbian Exchange and the demographic collapse of Indigenous America
After The Columbian Exchange and the demographic collapse of Indigenous America
After The Columbian Exchange and the demographic collapse of Indigenous America
After The Columbian Exchange and the demographic collapse of Indigenous America
After The Columbian Exchange and the demographic collapse of Indigenous America
After The Columbian Exchange and the demographic collapse of Indigenous America
After The Columbian Exchange and the demographic collapse of Indigenous America
After The Columbian Exchange and the demographic collapse of Indigenous America