The Guarani language is one of the official languages of Paraguay. Of the indigenous languages of the Americas it is one of the most widely spoken, and in Paraguay's case the majority of the population can speak it. Guarani can be found used by the people of Paraguay, from everyday transactions to art and literature.
The challenge here is to have a similar phenomenon occur in North America, where a country's primary spoken tongue is a descendant of an indigenous language.
The expansion of indigenous languages in the post-contact era does have precedent outside of Paraguay. In Mexico, Nahuatl's range increased as its speakers constituted most of the armies led by conquistadors into Central America and Northern Mexico. In Brazil, Tupi (later becoming Nheengatu) functioned as a lingua franca during the colonial era, thus spoken by the native inhabitants and Europeans alike.
Central America also provides interesting examples with the Miskito and Garifuna languages. Miskito is a Misumalpan language that became the most widespread of its family during the growth of the Miskito coast. The Garifuna language descends from Island Carib and spread from Dominica and St. Vincent to Central America following the deportation of it's speakers by the British. Both groups contain significant African influence.
Central America and the Caribbean are included in with North America. You can use any POD anywhere as long as it is after 1400.