Original: He is renowned as the first European since the Norse colonization of the Americas around AD 1000 to explore the Atlantic coast of North America between the Carolinas and Newfoundland, including New York Harbor and Narragansett Bay in 1524.
Simplified: He is known for being the first European since the Norse colonization of the Americas around 1000 AD to explore the Atlantic coast of North America between South and North Carolina and Newfoundland, including New York Harbor and Narragansett Bay in 1524.