The first European believed to have set foot on the mainland of North America is John Cabot, an Italian explorer, who sailed under the English flag. In 1497, Cabot reached the coast of what is now Newfoundland, Canada, and his journey is often credited with opening the door for future exploration and colonization of North America by European powers. His landing marked a significant milestone in history, contributing to England's later claims to territories in the New World and paving the way for further exploration.