| ca. 400,000 BP | Homo sapiens evolve in Africa. |
| ca. 25,000-14,000 BP | Glaciation exposes Beringia land bridge. |
| ca. 15,000 BP | Humans arrive in North America. |
| ca. 13,500-13,000 BP | Paleo-Indians use Clovis points. |
| ca. 11,000 BP | Extinction of mammoths. |
| ca. 10,000-3000 BP | Archaic hunter-gatherer cultures dominate ancient America. |
| ca. 5000 BP | Chumash culture emerges in southern California. |
| ca. 4000 BP | Eastern Woodland peoples grow gourds, make pottery. |
| ca. 3500 BP | Southwestern cultures cultivate corn. |
| ca. 2500 BP | Eastern Woodland cultures build burial mounds, cultivate corn. |
| ca. 2500-2100 BP | Adena culture develops in Ohio. |
| ca. 2100 BP-AD 400 | Hopewell culture emerges in Ohio and Mississippi valleys. |
| ca. AD 200-900 | Mogollon culture develops in New Mexico. |
| ca. AD 500 | Bows and arrows appear south of Arctic. |
| ca. AD 500-1400 | Hohokam culture develops in Arizona. |
| ca. AD 800-1500 | Mississippian culture flourishes in Southeast. |
| ca. AD 1000-1200 | Anasazi peoples build cliff dwellings and pueblos. |
| ca. AD 1325-1500 | Mexica establish Mexican empire. |
| AD 1492 | Christopher Columbus arrives in New World. |