When Columbus landed on the island-fringe of America in 1492, he thought he had found what he had set out to find—the eastern country of India; and he believed it all his life. This idea survived for several generations, partly because of the great wealth of Mexico and Peru. When Europeans were at last convinced that it was not India, they began again to seek a way to the East, and looked on the continent of America merely as an obstacle in their path.According to the passage, what did Columbus think he had found?