The main difference between the cultures of the Ancestral Puebloans and the Mississippians is that the Ancestral Puebloans were known for building stone homes while the Mississippians were known for building mounds.
This response accurately highlights a significant architectural distinction between the two cultures, with the Ancestral Puebloans associated with cliff dwellings and stone structures and the Mississippians known for their earthen mounds, which often served ceremonial or political purposes.