Final answer:
The 1890s were a turning point in American foreign policy history due to factors such as the acquisition of new territories and the need for overseas markets.
Step-by-step explanation:
The 1890s marked a turning point in American foreign policy history for several reasons. One key factor was the emergence of the United States as a global power after the Spanish-American War in 1898. The victory in this war led to the acquisition of new territories, such as the Philippines, Guam, and Puerto Rico, which prompted the need for the United States to develop a more assertive foreign policy. Additionally, the closing of the American frontier and the desire for overseas markets for American goods also influenced a shift in foreign policy during this time.