Since the 1500s sailors had longed for a shortcut between the Atlantic and Pacific Oceans.
Finally, in 1881, a French company made the first attempt at digging a canal through the isthmus of Panama, the narrowest stretch of land in Central America.
But the project was abandoned seven years later, after little progress had been made and 20,000 workers had died from accidents and disease, primarily yellow fever and malaria.
In 1902, U.S. president Theodore Roosevelt pushed through a plan that bought rights from the French company and negotiated a treaty with Panama.
Construction resumed under U.S. management in 1904, and the canal was opened in 1914.
Between 1881 and 1914, an estimated 80,000 people worked on the project.
It was one of the most ambitious and difficult engineering projects in history.
Yellow fever and malaria remained a problem at first, until U.S. Army doctor William Gorgas was brought in to help eliminate the diseases.
His colleague in Cuba, Dr. Walter Reed, had earlier discovered that the diseases were spread by mosquitoes.
It takes a ship about eight to ten hours to make the trip through the canal.
By using the canal instead of going around South America, a ship traveling from New York to San Francisco can shave nearly 8,000 miles (12,880 km) off its journey.
About 14,000 ships travel through the canal each year.