Known. Wall trenches and tiny drills were found in the ancient city of Cahokia.
Cahokia lies near modern St. Louis, Missouri. The Mississippian people began it in the 800s or 900s AD. In a layer from about 1100 to 1200 AD, diggers found wall trenches, the remains of buildings, pottery, and small tools called microdrills. Those walls and tools are about 800 to 900 years old.
The page does not say what is still argued.
https://www.ancient-origins.net/news-history-archaeology/cahokia-0020971