I can't speak to the First Nations of the United States but I can speak to the First Nations of Australia. While those nations inhabiting the interior of the continent, those regions devoid of coastline would have had little if any interaction with foreign people, it is possible that knowledge of the existence of foreign people's could have penetrated the Australian interior through oral communication with those nations inhabiting the coastal regions.

We know that Australian First Nations traded with seafaring civilisations of South East Asia, with one of the more popular traded commodities being the sea cucumber. Makassan Trepangers (collectors) hailed from Indonesia and travelled to the Northern regions of Australia to fish and harvest Trepangs, the prized sea cucumbers that were considered to be delicacy. The Makassans are known to have visited Australia from at least the 18th century and were interestingly enough Australia's first contact with Islam. These visits are believed to have been mostly peaceful with Makassans negotiating with First Nations for the right to fish in their waters. Turtles and Dewgongs were especially sought and the First Nations would often trade turtle for goods that were at that time outside of the First Nations technological capabilities to produce, certain cloths, some alcohol as well as tools such as metal axes. There is evidence however of violence but we do not know to what extent. We do know however that it was not just goods that were exchanged, we know that women were also exchanged and there is evidence to suggest that Australian First Nations people did willingly return to Indonesia with the Makassans.

Much of this evidence comes from Aboriginal cave art as well as some oral histories passed on in the tradition of the Australian First Nations.

This comes from a course on globalisation I undertook during university which dedicated a portion of the unit to early Australian international trade.