Final answer:
The majority of Spanish settlers in the Americas from the 16th to the 18th century were young unmarried men, including soldiers and clergy, seeking wealth and status through conquering and colonization under the Spanish Crown's encomienda system.
Step-by-step explanation:
The majority of Spanish settlers in the Americas from 1500 to 1800 were primarily young unmarried men. These men sought to acquire wealth and status in the new territories. Soldiers, clergy, and people loyal to King and empire came over as conquistadors and encomenderos, the latter being responsible for the control over lands and indigenous peoples granted by the Spanish Crown. The significant influx of these young men can be attributed to Spain's policy of bestowing conquered lands to proven loyalists, a system that also placed a strong emphasis on expanding Catholicism through the work of missionaries.
Specific figures, such as Hernán Cortés, who was a premier encomendero in New Spain, exemplify the type of individual who led and benefited from the conquest and colonization practices. This group played a pivotal role in Spanish colonization efforts over the course of three centuries, facilitating Spain's model of conquest that resembled their previous reconquest efforts in Iberia. While there were also administrators, artisans, and families that settled, the primary demographic consisted of these young unmarried males who had a significant impact on the societal and economic structures of the Spanish colonies.