Two millennia before Chaco Canyon, some of the earliest monuments in the Americas were constructed in the lower Mississippi valley. Monumental earthworks – pyramids, platforms, effigies, enclosures – continued to be built from 1000 BCE right up to the arrival of the Spanish, from Iowa to the tip of Florida. Some were enormous: Pyramids as large as almost anything in Mexico. Many are mysterious: serpent effigies, geometric enclosures large enough to surround a modern golf course. This talk will compare monumental building in the ancient Southeast and Southwest – particularly in light of differing regional traditions in their archaeological study.