Twenty-seven cities worldwide and a South-American country bear Columbus’ name, as do innumerable streets throughout Mexico.
No, Columbus wasn’t unique in believing the world was round. He argued that the world was small, with India to the east just beyond the point-of-no-return (when a ship was half-way done with its water). If he was wrong, everyone on the voyage would die. If he was right, well, the potential riches (silks and spices) could fuel an empire.