query: What was the first vessel to cross the Panama Canal?
passage: SS Ancon (1901)
SS Ancon was an American cargo and passenger ship that became the first ship to officially transit the Panama Canal in 1914. The ship was built as Shawmut for the Boston Steamship Company by the Maryland Steel Company, Sparrows Point, Maryland and put into Pacific service operating out of Puget Sound ports for Japan, China and the Philippine Islands. Shawmut and sister ship Tremont were two of the largest United States commercial ships in service at the time and the company eventually found them too expensive to operate.
passage: 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.