One hundred years ago, on August 15, 1914, the Panama Canal officially opened when the S. S. Ancon steamed through from the Atlantic to the Pacific side. The debut was quieter than intended because it was overshadowed by the widescale war that had just erupted in Europe, where 16 million men under arms were rushing into the fight, and thousands of soldiers had already died in early battles in Belgium and France.

The canal had been first discussed in the 16th century. By cutting the time required to travel around the southern tip of South America, trips between the Atlantic and Pacific oceans could be faster. And in the world of commerce and international trade, faster means cheaper and better. The French, flush with their success from digging and opening the Suez Canal in 1869, started work on the canal in Panama in 1881. This project, though, turned out to be much harder. The humidity, heat and muddy soil made digging difficult. Tropical diseases and accidents led to the deaths of more than 20,000 men. In 1904 the U.S. (having supported the secession of Panama from Columbia) bought the French machinery and the rights to finish the canal. With a new army of workers, the latest in steam-powered machinery and an intense focus on keeping workers healthy, the Americans battled through the muddy ground, digging deep and constructing gigantic concrete locks to raise and lower ships.

In the November 9, 1912, issue of Scientific American, an article written by the special commissioner on Panama traffic and tolls presented the advantages of the canal, unapologetically touting the benefits to U.S. commerce and defense: “The Panama Canal is being constructed to facilitate the commerce of the United States and of other countries, and to strengthen the efficiency and striking power of the American Navy. The great investment of capital has been made for the purpose of shortening ocean routes, first of all to enable the commerce between the Atlantic and Pacific to be handled more economically, and second, to add to the military power and prestige of the United States.”

A century later the canal is still a vibrant part of international trade and still contributes to U.S. military power (even though the U.S. no longer owns the canal). More than 900,000 ships have used the canal since it opened. And almost 5 percent of world trade passes through it today.

But the history of the canal is still being written. With cargo ships increasing in size--a few now exceed the “Panamax” sizes that fit in the locks--the Panama Canal Authority is building a third set of locks, scheduled for completion in 2015.

The concept of the Panama Canal has always had competition. Governments and engineers have discussed many alternatives to the canal. Even before it opened in 1914, several routes through Nicaragua had been proposed, and a railway was designed that would carry ships bodily over the narrow Isthmus of Panama from one ocean to the other. In a resurrection of one of those plans, the government of Nicaragua has joined forces with HKND, a Hong-Kong based group, to build a canal that would directly compete with the Panama Canal. The cost is projected at $40 billion. Some observers suggest the plan is entirely a propaganda ploy, but a report on the Maersk Line, owner of 20 of the largest cargo ships afloat (which are too big to fit through the Panama Canal), points out that the Nicaragua Canal “makes good sense.”

Scientific American has covered the Panama Canal since its inception, and also some proposed alternates.

The early years: construction and alternates, 1881–1912

The canal is opened, 1914

A Plan for Panama, 1999

New shipping lanes after the ice caps melt

New shipping lanes won’t open up after the ice caps melt

Panama today—a podcast visit with our own Steve Mirsky

A look from Nature on the environmental aspects of a brand new canal in Nicaragua

And every article we’ve ever had on great engineering projects such as the Panama Canal can be found in our Archive