Even for French diplomat Ferdinand De Lesseps, who considered the Suez Canal project a cakewalk, the Panama Canal project proved to be a life-and-death challenge.
The Suez Canal allowed De Lesseps to plow through the land "locklessly" (lockless channel). By contrast, with the Panama Canal project, he would have to cut through various elevations of the Continental Divide.
De Lesseps ignored all advice and started digging at sea level in 1880. Projected to be a nearly 10-year project, his futile strategy and financial mismanagement caused the death of 22,000 laborers. They died from both physical injuries from mostly landslides and disease. This crushed De Lesseps's confidence and the project.
United States to the rescue...
Then in 1903, United States President Theodore Roosevelt assumed the project's control when he bought out the French. He was concerned with the past failure of De Lesseps and his men, so President Roosevelt employed raised-lock engineering and disease prevention. Roosevelt sprayed oil on the breeding grounds of mosquitos to help eliminate malaria and yellow fever.
As of 1914, the Panama Canal was raised from a failure to a success.
Considered the world's last great project of this type, the Panama Canal changed sailing forever. The treacherous 14,000-mile sea journey from New York to San Francisco initially included the perilous tip of South America, Cape Horn. As a result of the canal's success, the sea journey was now a 6,000-mile pleasure cruise.
Read more about it at WWF.