Or to put it another way, is Christopher Columbus over-rated? Around the end of the 15th century, given the growth of European seafaring abilities, the incentives of trade, and the extremely regular Spanish and Portugese voyages to India around the Cape of Good Hope, was it not more or less inevitable that someone would have hit on something as big as the Americas?
First of all, consider that Brazil was “discovered” (a racist term that denies aboriginal rights, but let’s use it anyway) by a Portugese navigator, Pedro Álvares Cabral, who seems to have been blown off course in a trip that was orginally destined to round Africa and go to India. And what year was this? Why, 1500, only 8 years after Columbus reached San Salvador (indeed, Columbus was still alive then).
Why was Cabral blown to Brazil? Because the prevailing winds blew him in a south-westerly direction. This is perfectly normal, because in the northern hemisphere, the prevailing winds that blow between 30 degrees N. (roughly the latitude of northern Florida or southern Morocco) and the equator are the NE trade winds, so named because they blow from the north-east, towards the south-west.
In other words, the prevailing winds between Spain/Portugal/North-West Africa and Florida to Northern Brazil in the New World are just naturally disposed to blow ships on a westerly route.
Indeed, the westerly trade winds ar so strong that Columbus himself recorded that he was happy when, on his first voyage, a contrary eastward wind blew up for a day or two on September 22, 1492. “I needed such a wind”, wrote Columbus," because the crew now believed that there were winds in those seas by which we might pass to Spain." (See Columbus by Felipe Fernandez-Armesto).
In other words, having left the Canary Islands on September 6, 1492, by September 22, Columbus’ crew were actually starting to wonder if the wind in that part of the world could even blow in any direction but westwards!
Consider also that the Americas stretch in an unbroken land almost from the arctic to the antarctic.
I still admire Columbus, and I am something of a Columbus freak, although he was in fact wrong in his calculations, and the people in Spain who shot down his theories and recommended against his voyage were perfectly correct.
But given the state of winds, exploration and geography in the late 1400s, was it not pretty much inevitable that Europeans would have reached the New World with or without Columbus? Maybe not the same year, but around that time?