Which is the most likely reason why spain controlled so much of the americas in 1400s and 1500s?

Because they set out to go some where first.

Explanation:

"globalization has greatly impacted the united states and american citizens. first and foremost, globalization has spread american influence throughout the world. globalization has opened up more markets for the united states, which in effect american companies sell their products worldwide. there has been a rise of multinational corporations and their influence has greatly increased."

the award is named for an american naval historian and theorist, rear admiral alfred thayer mahan, united states navy who, through his writing, provided stimulus and guidance to those who share in the defense of the nation.