Final answer:
The primary factor responsible for the change depicted in the illustration is Overseas expansion associated with the Spanish-American War.
Step-by-step explanation:
The primary factor responsible for the change depicted in the illustration is A) Overseas expansion associated with the Spanish-American War. The Spanish-American War occurred in 1898 and marked the beginning of the United States' involvement in global affairs and its transition to becoming an imperial power. Through this conflict, the United States acquired territories such as Guam, Puerto Rico, and the Philippines, which positioned it as a dominant world power in the South Pacific and the Caribbean.