Which two geographic features most influenced united states foreign policy throughout the 19th century?

The Atlantic Ocean and Pacific Ocean are the geographic features that offered the most influence for the United States foreign policy during the 19th century. In the time prior, the world lived by isolationism. this meant that those in the US just fought neighboring territories, often striving to conquer entire continents in some cases. Once the 19th century rolled around, the US ha begun to have more interest in the oceans and maritime adventures. They began to claim more of the ocean lands for their country.

What does that mean mon