As it is pointed out in the passage, the Panama Canal ____ .

In 1903 the United States signed a treaty with Panama,
which gave the United States rights in perpetuity ever a 16
km wide strip of land extending across the narrowest part
of Panama for the purpose of building and running a
canal. The canal built, now known as the Panama Canal,
connects the Atlantic and the Pacific Oceans and is just
over 80 km long. Its depth varies from 12 to 26 meters. It is
constructed above sea-level, with locks and has been
available for commercial shipping since 3 August 1914. An
agreement was reached in 1978 for the waterway to be
turned over Panama by the end of the century.