Answer:
Manifest destiny
Step-by-step explanation:
Manifest Destiny was an idea that's popular win 1845. It's a belief that stated United States were destined-by God to spread Capitalism to all territories across North America.
Some part of north America at that time belong to Spain. This essentially become a catalyst for the Spanish-American war that occurred in 1898. Untied States managed to emerge victorious after the signing of Treaty of Paris in 1898