Final answer:
The main motivator for countries to become more imperialistic during the late 19th and early 20th centuries was the ability to gain wealth from other countries' resources.
Step-by-step explanation:
One of the main motivators for countries to become more imperialistic during the late 19th and early 20th centuries was the ability to gain wealth from other countries' resources. Industrialized nations sought to control colonies and territories in order to access inexpensive raw materials and establish markets for their goods.
This allowed them to expand their economies and gain economic advantages over their competitors.