They never figured out how to smelt copper, or to make brass or bronze.
The Aztecs in Mexico were just starting to learn how to smelt copper when they were discovered and conquered by the Spanish Conquistadors.
Given that 7,000 years ago, Indian precursors shaped the copper into tools, fishhooks, jewelry and other implements. I always wondered why the next step bronze didn’t occur. I did a quick search on tin deposits in the Americas and there seems to be very little tin in North America particularly the eastern Woodlands. The Central Americans did some bronze work. I guess overland travel was too difficult to set up trade routes. Also, with no larger draft animals to be beasts of burden long distance was difficult and inefficient.