The first Americans were hunters, gatherers, and fishermen, and this way of life continued in tropical rainforests and cold northern woods. Other peoples became farmers. In the Andes of South America they grew potatoes and herded llama. In fertile river valleys, MOUND BUILDERS grew corn, beans, and squash.
By 1279, the Mongol Empire covered over 33,000,000 km² (12,741,000 sq mi), up to 22% of Earth's total land area. It held sway over a population of over 100 million people.
