Panama Canal
France began work on the canal in 1881, but stopped due to engineering problems and a high worker mortality rate. The United States took over the project in 1904 and opened the canal on August 15, 1914. One of the largest and most difficult engineering projects ever undertaken, the Panama Canal shortcut greatly reduced the time for ships to travel between the Atlantic and Pacific Oceans, enabling them to avoid the lengthy, hazardous Cape Horn route around the southernmost tip of South America via the Drake Passage or Strait of Magellan.
Gatun Dam
As described in History of the Panama Canal, the canal effort was begun by a French company (La Compagnie Universelle du Canal Interoceanique) in 1880 to 1889. With poor exploration of the options and with poor information of the costs the French company planned to construct a sea-level canal linking the two coasts. They initially thought they could do this for about $120 million. After spending about one billion Francs (about $300,000,000) losing about 22,000 workers and going bankrupt the French effort essentially ceased. A sea level canal would not have required the dam to be built but would have still required extensive provisions made to accommodate the ever-changing Chagres River flow. When the United States took over the wide Canal Zone and resumed building the canal on 4 May 1904 almost two years were spent in infra-structure preparation, mosquito abatement (the newly discovered vector spreading Yellow fever and Malaria), Panama Railroad improvements and planning before the work got up to full speed. After reviewing the options and costs, in 1906 a lock-based canal was decided upon and agreed to by President Theodore Roosevelt.