History of the Panama Canal
During World War II, the canal proved a vital part of the U.S. military strategy, allowing ships to transfer easily between the Atlantic and Pacific. Politically, the Canal remained a territory of the United States until 1977, when the Torrijos–Carter Treaties began the process of transferring territorial control of the Panama Canal Zone to Panama, a process completed on 31 December 1999.
Panama Canal
The construction of the canal was completed in 1914, 401 years after Panama was first crossed by Vasco Núñez de Balboa. The United States spent almost $500,000,000 (roughly equivalent to $9,169,650,000 now) to finish the project. This was by far the largest American engineering project to date. The canal was formally opened on August 15, 1914, with the passage of the cargo ship .