It really is a great plant: Easy to grow even in bad soil, simple to harvest, full of starch, and easy to store without refrigeration. If you've got a sunny balcony and a big pot you can grow a fifty pounds a season, and you can start with potatoes you buy from the store.
While the Eastern hemisphere was breeding livestock the Western Hemisphere was breeding plants. (There's only one domesticatable animal in the Americas so they had some free time.) With that time they created potatoes, hot peppers, tomatoes, maize, squash, pineapples, peanuts, and many more.