European Exploration in the Americas

By the end of this lesson, students will be able to:

• Account for the reasons that drove European nations to launch long ocean voyages in the late fifteenth and sixteenth centuries.
• Identify the maritime technologies, including the caravel, the lateen sail, the magnetic compass, the astrolabe, and improved cartography, that made sustained Atlantic voyaging possible.
• Trace the sequence by which Portugal, Spain, France, and England entered the Atlantic, beginning with Henry of Aviz at Sagres and ending with the Cabot and Verrazzano expeditions.
• Apply Skill 1.A (Developments and Processes) to describe how the gold, God, and glory motives operated together rather than in isolation.
• Use the reasoning process of Causation to weigh which causes most directly explain the timing of European exploration after 1453.

European exploration of the Atlantic did not begin with Christopher Columbus. By the time Columbus left the harbor of Palos in August 1492, Portuguese caravels had already worked their way down four thousand miles of West African coast and were closing in on a sea route to India. What changed in the late fifteenth century was not the desire to reach Asia but the conditions that finally made the voyage thinkable. Those conditions, examined together, account for why European nations pushed across the Atlantic when they did and not earlier (KC-1.2.I.A).

The first condition was a closed door. In May 1453, Ottoman forces under Mehmed II captured Constantinople, the city that had served for a thousand years as the bridge between the Mediterranean and the overland caravan routes carrying spices, silks, porcelain, and precious stones from Asia to European ports. The Ottoman blockade did not end the long-distance trade entirely, but it sharply raised the price of Asian goods reaching Venice, Genoa, and the markets that fed northern Europe. Atlantic-facing kingdoms that had been spectators to the Mediterranean spice trade now had a direct economic incentive to find their own route to the source. Portugal and Spain, both with long Atlantic coastlines and neither with significant Mediterranean trading networks of their own, were positioned to do exactly that.

The second condition was new technology. Iberian shipbuilders combined two sailing traditions. The square sail, inherited from northern European practice, was efficient when the wind blew from behind the ship. The triangular lateen sail, borrowed from Arab and Mediterranean shipbuilders, allowed a vessel to tack against the wind. Combining the two on a single hull produced the caravel, a fast and shallow-drafted ship that could probe coastlines, ride open ocean, and beat its way home against contrary winds. Navigators paired the caravel with three instruments. The magnetic compass, adapted from a Chinese invention that had reached Europe via Arab traders, gave a reliable bearing when stars were hidden. The astrolabe, and later the simpler quadrant, allowed a navigator to measure the angle of the sun or polestar above the horizon and translate it into latitude. Improved cartography, especially the portolan charts produced in Genoese, Catalan, and Portuguese workshops, recorded coastlines, currents, and prevailing winds in steadily greater detail. Add gunpowder weapons that gave Europeans an edge in coastal encounters, and a fifteenth-century captain leaving Lisbon had survival odds his great-grandfather would not have recognized.

The third condition was political will. Portugal led, and the lead came from a single royal patron. Prince Henry of Aviz, a younger son of King John I and remembered later as Henry the Navigator, established a maritime study center at Sagres on the southwestern tip of Portugal in the 1420s. He gathered cartographers, astronomers, shipwrights, and pilots, and he funded a sustained program of voyages south along the West African coast. Each expedition pushed a little farther than the last, mapped a little more shoreline, and built a fortified trading post or two. By 1488, Bartolomeu Dias rounded the Cape of Good Hope at the southern tip of Africa. Ten years later, in 1498, Vasco da Gama reached the Indian port of Calicut, completing the sea route to the Indian Ocean spice trade that Henry's program had been chasing for seven decades.

Spain entered the Atlantic later and for a different reason. The kingdoms of Castile and Aragon spent most of the fifteenth century occupied with the Reconquista, the long campaign to expel the last Muslim rulers from the Iberian Peninsula. When the city of Granada fell to the combined forces of Ferdinand and Isabella in January 1492, the Crown suddenly had a battle-tested military, an empty treasury, and no obvious next project. Christopher Columbus, a Genoese mariner who had lobbied unsuccessfully at the courts of Portugal, England, and France, presented his proposal to sail west to Asia. Isabella accepted in April. By October he had reached the Bahamas. The reasoning in his commission combined wealth, prestige, and religious mission in a single document: he was instructed to seek gold, to claim land in the name of the Crown, and to extend Christian faith to whatever peoples he encountered.

The bargain that sorted out the early Iberian rush is the Treaty of Tordesillas, signed in June 1494 with papal endorsement. The treaty drew a meridian line through the Atlantic roughly 370 leagues west of the Cape Verde islands and assigned everything east of the line to Portugal and everything west of it to Spain. The line happened to cut across the eastern bulge of South America, which is why Brazil developed as a Portuguese colony while the rest of South and Central America became Spanish. The Treaty mattered for two reasons. It defused what could have become an open Iberian war over Atlantic claims. And it codified the principle, written into the accompanying papal bull Inter Caetera, that European Christian powers held a religious right to claim sovereignty over non-Christian lands. That principle, sometimes called the Doctrine of Discovery, would shape European colonial law for the next four centuries.

France and England arrived after Iberia and behaved differently from the start. John Cabot, a Genoese navigator sailing under an English commission, reached the rocky coast of Newfoundland in 1497, providing the legal basis for later English claims in North America. His voyages did not produce immediate settlement, but they alerted London to the fishing grounds of the Grand Banks, which would draw English, French, Basque, and Portuguese cod fleets across the sixteenth century. France entered through two expeditions: Giovanni da Verrazzano, a Florentine navigator hired by King Francis I, mapped the Atlantic coast from Cape Fear to Cape Breton in 1524, and Jacques Cartier made three voyages between 1534 and 1542, sailing up the St. Lawrence as far as the future site of Montreal and laying the groundwork for later French claims in Canada. Neither nation was ready to challenge Iberia directly in the sixteenth century. Both were positioning themselves for the seventeenth.

Three motives, often summarized as gold, God, and glory, ran through the entire program. Gold meant the wealth that voyages were supposed to produce: bullion from American mines, profits from the Asian spice trade, fortunes from African gold and ivory, and access to commodities such as sugar that European agriculture could not yet supply. The economic theory underwriting the wealth motive was mercantilism, which held that a nation grew strong by accumulating precious metals and running a favorable balance of trade. Glory captured the rivalry among European courts: a Crown that sponsored a successful voyage gained prestige, strategic advantage, and political payoff at home. God referred to the religious mission. Every Iberian expedition carried priests; the Treaty of Tordesillas was framed as a Christian bargain; and missionary orders, especially the Franciscans, Dominicans, and later the Jesuits, accompanied conquistadors from Mexico to the Andes to the Philippines. The three motives reinforced one another. None of them, taken alone, accounts for why European exploration accelerated when it did. Together they explain the timing.

The five sources below trace the arc of European exploration: an early Spanish map drawn by a pilot who had sailed with Columbus, the letter that gave the new continent its name, the papal bull that justified the Iberian claim, an early sixteenth-century map of the North American interior, and an English voyage that broke the Iberian monopoly at sea.

1. (Causation) Identify the three pressures that pushed Atlantic-facing European kingdoms outward in the late fifteenth century. Which of the three would you rank as the primary cause of European exploration after 1453, and on what evidence?
2. (Causation) Trace the causal chain that runs from the fall of Constantinople in 1453 to Columbus's commissioning in 1492. At which step in the chain do you think a different decision could have produced a different outcome, and why?
3. (Causation) The lesson argues that the gold, God, and glory motives reinforced one another. Test that argument by asking what would have happened if any one of the three had been absent. Could Iberian exploration have proceeded with only two of the three motives in place?
4. (Skill 1.A) Account for the role of Prince Henry of Aviz and the Sagres school in the Portuguese voyages. What does the Henry-Sagres example reveal about the relationship between state sponsorship and exploration?
5. (Causation) The Treaty of Tordesillas appears to be a diplomatic settlement between Spain and Portugal. Account for how a bilateral Iberian agreement set boundaries that shaped French and English colonial choices a century later.

Draft alignment — pending educator review. AP USH codes correspond to the official College Board Course and Exam Description (Effective Fall 2023, Version 1). Statements below are paraphrased in the CountryReports voice; refer to the College Board's published CED for verbatim wording.