How it began
A French company headed by Ferdinand de Lesseps started building a canal across Panama in 1881 and failed by 1889. After Panama's independence, the United States obtained control of a Canal Zone under the Hay-Bunau-Varilla Treaty and began work in 1904. Tens of thousands of laborers, mostly from Barbados, Martinique and Guadeloupe, built the canal, which was completed in August 1914. It was built by the United States on Panamanian territory.
Before it existed
Before the canal, goods and passengers crossed the isthmus on the Panama Railroad, opened in 1855, or ships sailed around South America. The French sea-level project of the 1880s had shown how hard the terrain and climate were, and it ended in failure in 1889.
How it works
The canal is a lock canal, not a sea-level cut. A mountain range runs the length of Panama and the tides of the two oceans differ, so ships are raised by locks from sea level to Gatun Lake, a 166 square mile reservoir formed by damming the Chagres River, and lowered again on the far side. The locks fill and empty by gravity flow of water from the lakes. The original chambers are 1,000 feet long and 110 feet wide.
Where it stands today
Britannica describes the canal as one of the two most strategic artificial waterways in the world. The United States ran it for most of the twentieth century. Complete control passed to Panama at noon on December 31, 1999. Panama operates the canal. A third set of larger locks, begun in 2007 and completed in June 2016, added water-saving basins and allows bigger ships to pass. The canal measures about 40 miles from shoreline to shoreline and about 50 miles between deep water in the Atlantic and deep water in the Pacific.
