Answer:
The main motivations why the European powers (mainly Spain, Portugal, France and Great Britain) began to explore and occupy the American continent were the amount of valuable natural resources that were in the continent, such as gold, silver, food, etc., which could be used by European nations to enhance their mercantilist economies.
In addition, it was a time and a political context in which the greatness and power of nations is mediated according to their territorial extension. Thus, a huge continent like America gave these nations the possibility of expanding their dominions, controlling the seas and politically surpassing their adversaries.
It was precisely for these reasons that a century after the discovery of America, competition between nations increased, with the arrival of other nations such as the Netherlands or Russia, which also tried to establish colonies and obtain their share in the territorial and economic distribution of the continent.