When it comes to real American civilisations, one could look no further than in Mesoamerica and to some extent, the Incas of parts of South America proper. The biggest problem with most American countries is that as colonies they’re offshoots of European empires like Britain and Portugal. Brazil for awhile was known as United Kingdom of Portugal, Brazil and Algarves.
Canada’s still ruled by Britain as are New Zealand and Australia. Mexico’s also subjected to Spanish colonisation but prior to that, it already had its own civilisations like Mayans and Aztecs. Incas were like that in Ecuador, Peru and Bolivia. There could be several more within America itself, the biggest problem most of the Americas is that whatever Native American cultures they hosted were practically marginalised by colonisation.
But the same can be said of any country subjected to an empire to varying degrees.