Why is it difficult to say who discovered america?

There are many reasons on why it is difficult to say who discovered America.

Explanation:

For a long time, most people believed that Christopher Columbus was the first explorer to "discover" America-the first to make a successful round-trip voyage across the Atlantic. Now many think Irish Monks discovered America. Many also think the Vikings, and of course, the "Indians." There is also a theory about China being first.

Christopher Columbus official set foot in the America's, and claimed the land for Spain. But to say he discovered America is a bit of misnomer because there were plenty of people already here when he arrived