Do you believe Christopher Columbus really discovered America?

How do we know that Christopher Columbus really discovered america?Everyone recognizes that many people were in America long before Columbus. The Asiatic peoples who became Native Americans were certainly the first, tens of thousands of years ago. Also Norse expeditions to North America, starting with Bjarni Herjolfsson in 986, are well established historically. Many other pre-Columbian discoveries are not well established. Claims have been made for St. Brendan, Basque fishermen, Portuguese, Chinese, Japanese, Africans, and even Carthaginians. Some of these claims may be true; most are probably not.