Hohokam, Anasazi, First humans arrive in the Americas Agriculture begins in the present-day Southeast Poverty Point flourishes in present-day Louisiana The Olmecs begin to build the first Mesoamerican cities Agriculture begins in the Western Hemisphere Agriculture spreads from Mesoamerica to the present-day Southwest Adena culture reaches its height in North America Significant Events Mogollon culture flourishes in present-day New Mexico Mississippian civilization reaches its height Hopewell culture thrives in the Ohio and Mississippi valleys The Mayan civilization flourishes on the Yucatán Peninsula Anasazi civilization reaches its height and Mississippian civilizations decline; Apache and Navajo peoples enter the Southwest from Canada Aztec empire rises in Mesoamerica