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 Department
The Isthmian Canal Commission and the Panama Canal Guard of 1904–1914 both played a pivotal role in the construction and early defense of the Canal. With the active support and encouragement of the United States, Panama declared its independence from Colombia on 3 Nov. 1903 and that same month, the United States received the right to build and administer the Panama Canal.