Final answer:
The major era in Texas history associated with European explorers, large ships crossing the Atlantic Ocean, and conquistadors in search of gold is the Spanish Colonial era.
Step-by-step explanation:
The major era in Texas history that is associated with the characteristics of European explorers, large ships crossing the Atlantic Ocean, and conquistadors in search of gold is Spanish Colonial era.
During the Spanish Colonial era, Spain led the Age of Discovery and dominated the New World, including Texas. Spanish explorers, such as Christopher Columbus, set off on voyages in search of new lands and riches, and they established colonies in the Americas. These explorers crossed the Atlantic Ocean on large ships and encountered native peoples on their quest for gold.