At the time of columbus's arrival in the western hemisphere, where were the greatest concentrations of native americans prior to the arrival of columbus?

The largest Indian populations before the arrival of the Spanish were found in Mexico, Central America and South America (Inca Empire, Peru, Ecuador, Bolivia today).

Explanation:

you aint got nothin on my lil weenies

. political or economical policy that isolates a country from participating in international relationships. it has been suggested that the united states participates in isolationism because of its lack of involvement in particular wars or alliances.