A multi-country, multi-decade project that spans two oceans, the 50-mile Panama Canal was completed in 1914 and helped turn the United States into an economic juggernaut.

1. THE SPANISH SOUGHT A CANAL ROUTE IN THE 1500s.

Explorer and conquistador Vasco Núñez de Balboa first spotted the Pacific Ocean in 1513 and claimed the surrounding land, and the entire expanse of water, for the Spanish kingdom. Although he was later executed for treason, Balboa’s discovery led King Charles I, also Holy Roman Emperor Charles V, to issue a decree in 1534 ordering the regional governor of Panama to seek a route to traverse the Isthmus of Panama by way of the Chagres River. The plan was abandoned, being deemed impossible for the times. When it opened in 1855, the Panama Railroad was the main transportation route across the Isthmus.

2. THE FRENCH BEGAN THE CANAL PROJECT.

The trips around Cape Horn at the tip of Chile and around South Africa’s Cape of Good Hope remained the only viable water-based shipping routes from Europe and the Americas to Asia, a voyage that could add an additional 8000 nautical miles to a journey. But after completing the Suez Canal in Egypt in 1869, French consul Ferdinand de Lesseps led a team of engineers and builders in 1880 on the beginning of construction of the sea-level canal in Panama. The team encountered myriad problems, with the tropical heat, heavy rainfall, landslides, sickness, and the death of 20,000 workers ultimately causing them to halt work on the canal in 1888, and funding was soon pulled on the bankrupt project.

3. THE U.S. 'STOLE' PANAMA FROM COLOMBIA.

After declaring independence from Spain in 1821, Panama became a part of the Republic of Gran Colombia, which also included Venezuela, Ecuador, and parts of Peru, Guyana, and Brazil. In 1830, the country dissolved, and one of the remnant pieces was New Granada (eventually renamed Colombia), which corresponded roughly to modern-day Panama and Colombia. As the Canal project languished, the U.S. Isthmian Canal Commission was established in 1899 to study a potential water route, and the U.S. agreed to purchase France’s canal assets for $40 million a year later.

The Colombian Senate rejected the proposed Hay-Herrán Treaty in 1903, however, which would have provided financial compensation in exchange for America’s use of the Isthmus. Panama, with the tacit backing of the United States and the Panama Canal Company, declared independence from Colombia on November 3, 1903. The U.S. helped block the use of the railroad and stranded Colombian troops, while the gunboat USS Nashville lurked offshore (officially to “protect American lives in Panama”). On November 18 the Hay-Bunau-Varilla Treaty was signed, which gave the U.S. permanent and total permission to use the Panama Canal Zone.

4. TEDDY ROOSEVELT WAS INSTRUMENTAL IN THE CANAL’S CONSTRUCTION.

Former U.S. President Ulysses S. Grant had established the Inter-Oceanic Canal Commission in 1869 to study possible routes across Central America and sent seven separate expeditions to Panama, but ultimately decided the idea was too expensive to pursue. Roosevelt, succeeding the assassinated William McKinley in 1901, spoke of the need to build the Canal in a speech to Congress: “No single great material work which remains to be undertaken on this continent is of such consequence to the American people.” In addition to buying French assets, Roosevelt helped negotiate a one-time $10 million payment to the newly formed country of Panama, agreed to pay the nation $250,000 a year, formally recognized Panama’s independence on November 6, 1903, sent warships to the Atlantic and Pacific sides of the isthmus to intimidate Colombian forces, and established the Isthmian Canal Commission (ICC) on March 3, 1904, telling those in charge to “make the dirt fly.”

5. THE FIRST CANAL BOSS QUIT ABRUPTLY.

In June 1904, the U.S. took over work on the Canal where the French had left off. Chief Engineer John Findley Wallace, who was paid $25,000 a year (the highest government salary in the nation other than the president) was put in charge of the project but quickly grew frustrated with the country’s poor infrastructure, aging equipment, and rabid diseases that devastated workers. He resigned within a year.

6. THE SECOND BOSS STOPPED WORK ON THE CANAL.

One of the first tasks undertaken by new Chief Engineer John Stevens, who was known for his work on the Great Northern Railway, was to halt excavation work and rebuild the rail system to allow for faster and more efficient removal of the tons of dirt and rock being taken from the earth. Stevens, who improved morale among the workers by installing a food car, mess kitchens, and a school for children, scrapped the sea-level canal and asked the ICC to approve a lock system with a dam and artificial lake. Despite receiving plaudits from Roosevelt and greater decision-making powers, Stevens resigned on February 12, 1907.

7. THE PROJECT LITERALLY MOVED MOUNTAINS.

Following Wallace and Stevens was George Washington Goethals, an Army Colonel who had completed lock projects with the Army Corps of Engineers. His main task, in addition to overseeing work damming the Chagres River, was to excavate the Culebra Cut through Gamboa and Pedro Miguel. Also called the Gaillard Cut (named for Army engineer Lt. Col. David Gaillard), the 8-mile stretch of hills required up to 6000 workers using steam shovels, dynamite, and drills to haul over 180 million cubic yards of earth.

8. THE MOST IMPORTANT OFFICIAL MIGHT HAVE BEEN THE SANITATION OFFICER.

One of the first American arrivals after the takeover of the Canal was Dr. William Gorgas, the Chief Medical Officer, who was tasked with combating the deadly spread of malaria and other diseases that wiped out such a huge proportion of workers when the French controlled the Canal. Gorgas’s superiors, however, didn’t believe his theory that mosquitoes were the cause of both yellow fever and malaria, until Stevens took over and gave Gorgas his full support to step up efforts to eliminate the diseases. Teams of sanitation workers put up screens, fumigated homes, and provided running water to area towns.

While the last case of yellow fever was reported in 1905, malaria proved harder to beat, even infecting Gorgas, but workers continued their efforts. Gorgas and his wife Marie would later describe fighting malaria as “like fighting all the beasts of the jungle.” Swamps were cleared, vegetation was slashed and burned, ditches were built, insecticide was used liberally, and the rate of malarial infection plummeted from 7.45 in 1000 in 1906 to 0.30 in 1000 by 1913.

9. THOUSANDS OF MIGRANT LABORERS WORKED ON THE CANAL.

In sweltering 100-degree tropical heat, up to 40,000 workers contributed to the physical labor required to build the Canal. Most of the workers came from the Caribbean islands of Barbados, Martinique, and Guadeloupe, and the United States opened a recruiting agency in Barbados to attract employees, with some estimating that 30 to 40 percent of the island’s adult male population was recruited to the Isthmus.

10. FLOODS AND LANDSLIDES DECIMATED EARLY EFFORTS.

Speaking before the House Committee on Interstate and Foreign Commerce, Stevens reiterated the need to forgo a sea-level canal, telling the members, “the one great problem in the construction of any canal down there is the control of the Chagres River.” The French had struggled with flooding during their failed attempt, and the infamous Cucaracha Landslide in 1907 slowed progress and moved 500,000 cubic yards of debris into the Culebra Cut. More landslides in 1912 at the Culebra Cut required four and a half months to dig out.

11. ENGINEERS CONSTRUCTED THE WORLD’S LARGEST ARTIFICIAL DAM.

Finally eschewing the idea of a sea-level canal in 1906, workers built a dam across the Chagres River, which crisscrossed the path of the proposed canal route and varied widely in its flow rate due to intense rainfalls. The dam, completed in 1913, created the Gatún Lake, which was the largest man-made lake in the world and formed more than 20 miles of the canal route. In addition to the dam, engineers devised a set of locks, first begun at Gatún in 1909, that form the core of the Canal’s function. Each lock chamber, built in pairs to accommodate two-way traffic, has identical dimensions of 110-by-1000 feet. Gravity powers the entire system, as water is diverted through culverts into the locks, raises ships 85 feet to the surface of Gatún Lake, and lowers the vessels back to sea level on the Ocean side.

12. THE CANAL OPENED AFTER THE OUTBREAK OF WWI.

In early August, 1914, Germany declared war on both Russia and France, signaling the start of the first World War. Less than two weeks later, on August 15, the Panama Canal officially opened, although the ceremony that originally included a fleet of international warships and visits from foreign dignitaries was significantly tempered due to the conflict in Europe. The first ship to officially pass through the Canal was a cement boat called the Ancon.

13. IT BECAME THE MOST EXPENSIVE PROJECT IN U.S. HISTORY.

Although the Canal came in well under budget (about $23 million below the original 1907 estimate), at $375 million it was the most expensive construction job ever undertaken by America. That cost included the $10 million and $40 million payouts to Panama and France, respectively. Original toll costs were $.90 per cargo ton, a price which stayed the same until it was raised to $1.08 in 1974.

14. IT IS A MODERN WONDER.

In 1994, the American Society of Civil Engineers released a list of the Seven Wonders of the Modern World. Along with the Panama Canal, which author David McCullough called “one of the supreme human achievements of all time,” the other wonders on the list were the Channel Tunnel built between England and France; the CN Tower in Toronto, Canada; the Empire State Building in New York City; San Francisco’s Golden Gate Bridge; the Itaipu Hydroelectric Dam in Brazil and Paraguay; and the Netherlands North Sea Protection Works.

15. THE PANAMANIAN GOVERNMENT FINALLY TOOK OVER IN 1999.

Although a pair of treaties signed between the two countries relinquished a little bit of America’s control of the area, it wasn’t until 1977 that President Jimmy Carter signed the Panama Canal Treaty (which was approved by the Senate in 1978), which abolished all previous agreements, set up a 20-year transition period for the U.S. to cede management of the Canal, and gave Panama sovereign powers over the former Canal Zone. On Dec. 31, 1999, Panama officially gained control of the Canal.