Around 1900 the world ran on Amazon rubber, which built marble opera houses upriver and produced a great atrocity on the Putumayo, where Julio César Arana's British-registered company enslaved, tortured, and killed Huitoto and Bora people. Three witnesses exposed it, and smuggled seeds then collapsed the boom around 1912. Henry Ford's Fordlandia closes the story, and the worst actors were British-registered Peruvian capital, not American.
The Putumayo death toll is genuinely contested, with estimates ranging widely and records deliberately poor. Scholars also debate whether to call it genocide or an extreme labor regime of terror.