During the age of exploration, European countries explored new lands for political, religious and economic reasons. The explorations of the 15th and 16th centuries were fueled by a growing desire for expansion and trade, advances in shipbuilding and commerce, and the search for new markets and for the legendary sources of precious metals and
Portugal took a leading role during most of the fifteenth century in searching for a route to Asia by sailing south around Africa, allowing the Portuguese to accumulate a wealth of knowledge about navigation and the geography of the Atlantic Ocean. Their explorations were colored by the European world view in the late 15th century based upon imaginings about the unknown and scientific observations of the known. Maps created during this time illustrate a Medieval world view laid out into three continents, but also record real and imagined countries.
Spain’s explorations were driven by the desire to expand its knowledge of the world, to discover spices and riches and to expand Christianity. In 1492, when Christopher Columbus, sailing for Spain, took a westerly course across the Atlantic Ocean searching for an alternative route to the Indies, he inadvertently “discovered” a new continent.
Source: Hispanic Exploration in America