Final answer:
The ancient structures in question were built using earth, along with materials like wood, brick, stone, and mud bricks. The construction of these large mounds in North America, particularly by the mound builders of the Mississippi, reflected complex organized efforts by skilled craftsmen and conscripted labor.
Step-by-step explanation:
The student's question seems to be referencing the construction of large ancient structures in North America. One of the largest indigenous earthen structures north of Mexico, often attributed to the mound builders of the Mississippi, was built using earth to create a massive mound. This structure, considered a grand earthen truncated mound, was the most significant of its kind on the Mesoamerican peninsula, rising over 34 meters from the natural level countryside.
Materials such as wood, brick, stone, and mud bricks were used in the construction of various large structures in ancient times, and techniques such as the post and lintel system were common for shorter distances. Advanced societies across the world have been known to move colossal stones and materials to create monumental structures, as seen in the examples of Stonehenge, the Greek Parthenon, and the pyramids of Egypt.
It is noteworthy that the workforce responsible for such constructions, including the Mississippi mounds, consisted of a combination of permanent skilled craftsmen and seasonal crews of conscripted peasants, indicating an organized and complex society capable of undertaking such large-scale projects.