The Short Version
The claim is well-supported. Multiple high-authority sources — including the Library of Congress and NASA — confirm that Columbus's 1492 voyage aimed to find a westward trade route to Asia, not to prove Earth was round. Educated Europeans had accepted Earth's spherical shape for centuries, drawing on ancient Greek scholarship and medieval thinkers like Thomas Aquinas and Roger Bacon. The flat-Earth myth surrounding Columbus was largely a 19th-century fabrication. The real debate in 1492 concerned Earth's circumference and the feasibility of the westward route.