Crossing from N. America to the east was an infrequent possibility because the new world was an inhospitable and sparsely populated place.
The reasons could be asteroid impacts in the Hudson bay area and Chesapeake compounded by great floods from the many ice ages. From the west the impact of mega eruptions at Yosemite could have proved deadly all the way to the coast. There may have been no Gulf stream for navigation assistance in those times of antiquity.

Central America was a far friendlier and populated place. There is evidence from the six foot tall carved stone spheres of faces showing every race on earth and is attributed to be from the Olmec civilization pre dating the Aztec and Inca.

It is not obvious exactly who the sailing societies were.