What two European countries dominated trade in the Atlantic during the late fifteen century?

During the late fifteenth century, Spain and Portugal dominated trade in the Atlantic. Both nations were at the forefront of exploration and established extensive maritime routes, facilitating the exchange of goods, resources, and ideas between Europe, Africa, and the Americas. Their rivalry and subsequent treaties, such as the Treaty of Tordesillas in 1494, helped define their colonial spheres of influence in the New World.