Final answer:
Maize entered the Southeast through the adoption of maize agriculture, which led to significant changes in the region's agriculture.
Step-by-step explanation:
Maize entered the Southeast around 800 CE through the adoption of maize agriculture by groups already practicing farming edible plants. The Mississippian tradition, which emerged as a result of adopting maize agriculture, spread throughout the Eastern Woodlands, leading to the rise of large agricultural communities across the Mississippi River valley. Maize cultivation became common in the Southwest around 2250 BCE, with groups in the Las Capas area developing sophisticated irrigation systems. The introduction of maize changed agriculture in the Southeast by enabling the growth of dense populations, supporting specialized artisans, and leading to the rise of social hierarchies.