On what geographical area did the us concentrate in order to expand its influence during the late 1800s and early 1900s?

During the late 1800s and early 1900s, the US concentrated their expansion to the Caribbean Sea and some parts of the Pacific Ocean. These areas were targeted for their economic strategic locations as well as their access to ports for Naval bases.

Their expansion was a success when U.S. Gained control over Cuba and Puerto Rico in the Caribbean, and the Philippines and Guam in the Pacific.