Amajor factor in the shift in american foreign policy toward imperialism in the late nineteenth century was the
a. need for additional population.
b. construction of an american-built isthmian canal between the atlantic ocean and pacific ocean.
c. closing of the frontier.
d. need for overseas markets for increased industrial and agricultural production.
e. desire for more farmland.

d. need for overseas markets for increased industrial and agricultural production.

Explanation:

The US changed deeply its policy from isolationism into imperialism around the 19th century. Industrialization in the US created the necessity to seek new international markets to sell American goods. Because of that a belief that the US was destined to spread democracy, industry, and civilization around the world was created. The US started to control countries such as the Philippines, Cuba, Germany, Austria, Korea, Hawaii, and Japan.