Scientists rely heavily upon which kind of evidence to learn about early American Indians like the Mississippians?

They rely heavily on various craftwork.

Explanation:

Mississippian culture, the last major prehistoric cultural development in North America, lasting from about ad 700 to the time of the arrival of the first European explorers. The distribution of temples suggest a dominant religious cult and a cadre of priest-rulers who could command the services of a large, stable, and docile population, as well as several artist-craftsman guilds.

Craftwork was executed in copper, shell, stone, wood, and clay and in such forms as elaborate headdresses, ritual weapons, sculptured tobacco pipes, effigy pottery, effigies, and masks of wood or copper-jacketed wood.

It spread over a great area of the Southeast and the mid-continent, in the river ... American Indian ... since as early as 850 bc, but it had not diffused into North America until the advent of the ... Mississippian culture: copper workResearchers studying the pre-Columbian copper ... Learn More in these related Britannica articles:.