One thing I haven’t seen mentioned here yet is climate differences. North America has seasonality, and winters to contend with. The Central and South American civilizations generally dealt with wet and dry season, but food plants could always be growing. There are cities like Cahokia in North America that come about once corn agriculture is well established, allowing for stores of food large enough to support a large population through a winter. Throughout the world, monumental architecture only pops up once food abundance is possible.
Latest Answers