How closely related are Native Americans and MesoAmericams? Why are their cultures so different? Do they share similar genetics? And most importantly why did native Americans never build grand structures like the MesoAmerican Mayans and Aztecs?
This answer to a similar question might have some information that would interest you: u/pizzapicante27 also included links to even earlier questions in the same vein as yours.
This answer focuses on cities and structures built by indigenous people north of Mexico.