Columbus' discovery of land across the Atlantic became common knowledge across Europe fairly rapidly. He actually landed in Lisbon, Portugal first on his return in 1493, and told the tale of his expedition to King John II of Portugal before sailing on to Spain and reporting to the Spanish monarchs, Ferdinand and Isabella, who were his sponsors. The news spread across Europe from both Portugal and Spain.

This did not, however, mean that "The New World" became common knowledge. Columbus thought he had reached Asia by sailing west, not that he had reached a "New World".

The idea that Columbus' discoveries were a "New World" was first expressed by Amerigo Vespucci in two accounts published in 1502 and 1504. In 1507, Martin Waldseemuller published a map of the new discoveries showing them as a separate continent and islands, which he named "America" after Amerigo Vespucci. (He also attached to his map one of Vespucci's accounts stating Vespucci's theory that these lands were a "New World").

It was really this map that most publicized the concept of "The New World". Thus, this became 'common knowledge' across Europe fairly quickly after 1507.

Of course, whether a blacksmith, farmer, or cobbler would be aware of this is unknown. Given that 50% of Americans today cannot locate India on a map, 30% cannot point out the Pacific Ocean, and 85% cannot identify Iraq, it is very hard to say how much geographical knowledge a putative cobbler, blacksmith or farmer might have had 500 years ago.