Final answer:
The United States gained the most from the opening of the Panama Canal in 1914, significantly aiding in maritime commerce and military mobility between the Atlantic and Pacific.
Step-by-step explanation:
The opening of the Panama Canal in 1914 was a significant event that altered global shipping and military strategies. Primarily, the United States benefit from the Panama Canal as it dramatically reduced the shipping distance and time between the East and West coast, demonstrated as a strategic advantage when the U.S. Pacific Fleet needed to engage Spain after defeating them in the Philippines. However, the entire project would not have succeeded without dealing with the tropical diseases that plagued workers, a feat accomplished by Dr. William Gorgas who, with the help of Cuban researchers, eradicated the spread of malaria among workers. Moreover, the construction of the canal was a massive effort in engineering and logistics, involving the excavation of millions of cubic yards of earth and the construction of a complex lock system. The canal was constructed with the intention of providing a quicker passageway for cargo and military vessels between the Atlantic and Pacific oceans, thus benefiting commercial and military interests.