See the other comment by simonh in this discussion (https://news.ycombinator.com/item?id=9261989): Columbus had a multiplicity of detractors because his estimate of the circumference of the Earth was off by a factor of 2, and to his dying day insisted he'd found the East Indies, not the very fortuitous West "Indies". If the Americas weren't there, he'd be at best a footnote in history, a crazy explorer who'd perished with his crews.