Final answer:
The United States built the Panama Canal to enable quicker movement of the navy between oceans.
Step-by-step explanation:
The United States saw the need to build the Panama Canal as a result of the Spanish-American War because the United States navy could then move more quickly between oceans. Prior to the construction of the canal, ships had to sail south around the tip of South America in order to travel between the Atlantic and the Pacific. The canal reduced travel time and provided a more efficient route for the US navy.
Learn more about US Expansionism and the Panama Canal