How the Panama Canal was built: the French failure, the mosquitoes, the Culebra Cut, the locks and Gatun Lake, ten years and 25,000 dead

Architecture · 4 September 2026

The Panama Canal was built by the United States between 1904 and 1914, after a French company under Ferdinand de Lesseps, the builder of Suez, had failed between 1881 and 1889 with the loss of 22,000 lives and 287 million dollars; it runs 50 miles (82 km) from the Atlantic to the Pacific across the Isthmus of Panama, lifting ships 85 feet (26 m) in three locks to Gatun Lake, an artificial lake made by damming the Chagres River, carrying them across the lake and through the 9-mile Culebra Cut blasted through the continental divide, and lowering them in three more locks to the other ocean. It cost the Americans 352 million dollars and 5,600 lives, most of them West Indian labourers, and it succeeded where the French had failed for three reasons: the decision to build locks rather than a sea-level ditch, the conquest of yellow fever and malaria by William Gorgas, and the organisation of the digging as a railway problem by John Stevens. Below: the French attempt, how the Americans got the canal, the mosquitoes, the plan, the cut, the dam and the locks, the workers, the opening and the canal since, the numbers, and the disputes.

The French attempt, 1881–1889

De Lesseps, the diplomat who had built the Suez Canal in 1869 through flat desert, raised money from 800,000 French investors in 1880 for a sea-level canal across Panama, then a province of Colombia, on the route of the American railway of 1855, and began digging in 1881 with the best French engineers and machinery of the age, in a place with 200 inches of rain a year, a river, the Chagres, that rose 30 feet in a night, a mountain ridge of clay at Culebra that slid back into the cut as fast as it was dug, and yellow fever and malaria that killed the engineers as fast as they arrived; the hospitals kept the legs of the beds in bowls of water against ants, breeding the mosquitoes that spread the disease. The company dug about 60 million cubic metres, two-fifths of what the canal needed, changed to a lock plan too late in 1887 with Eiffel building the locks, and went bankrupt in February 1889, in a scandal of bribed deputies and newspapers that sent de Lesseps's son to prison and ruined the investors; some 22,000 workers, French, Jamaican and Colombian, had died. A new company kept the concession and the machinery rusting in the jungle, and sold it all to the United States in 1904 for 40 million dollars. Panama Canal.

How the Americans got it, 1903

The United States, after the Spanish–American War of 1898, when the battleship Oregon had taken 67 days to sail from San Francisco around Cape Horn to Cuba, wanted a canal and had chosen Nicaragua until the French company's lobbyist Philippe Bunau-Varilla and the lawyer William Cromwell, with a Nicaraguan stamp showing a volcano sent to every senator, turned Congress to Panama in 1902. Colombia's senate rejected the treaty in 1903, and Theodore Roosevelt, with Bunau-Varilla organising the Panamanian separatists and the cruiser Nashville arriving at Colón, saw Panama declare independence on 3 November 1903 and recognised it within hours; Bunau-Varilla, as Panama's minister, signed the Hay–Bunau-Varilla Treaty on 18 November before the Panamanians reached Washington, giving the United States a ten-mile-wide Canal Zone "in perpetuity" for 10 million dollars and 250,000 a year. "I took the Isthmus," Roosevelt said later, and Congress could debate it afterward. The Zone remained American until the Torrijos–Carter treaties of 1977 handed the canal to Panama at the end of 1999.

The mosquitoes

In 1900 Walter Reed's commission in Cuba had proved Carlos Finlay's theory that yellow fever was carried by the Aedes mosquito, and Ronald Ross had shown in 1897 that malaria was carried by Anopheles; the first American chief engineer, John Wallace, arrived in 1904 with a coffin, and the yellow fever of 1905 sent three-quarters of the Americans home. William Gorgas, the army doctor who had cleared Havana of yellow fever in 1901, was given a free hand in 1905 after Roosevelt overruled the commission that thought mosquitoes a fad: 4,000 men fumigated every house in Panama City and Colón, screened the windows, drained and oiled the pools and ditches, cut the grass, piped water so that households stopped keeping it in jars, and swept the Zone for larvae; the last yellow fever case was in November 1905, and malaria fell from 800 cases per thousand in 1906 to 16 by 1913. Without Gorgas the canal could not have been built; his campaign cost about 20 million dollars and is the founding work of tropical public health.

The plan: locks, not a ditch

The choice in 1906 was between a sea-level canal like Suez, which the French had attempted and a majority of the consulting board still recommended, and a lock canal with a lake at 85 feet, which John Stevens, the chief engineer from 1905 to 1907, argued for and Roosevelt and Congress chose: a sea-level cut would have needed a channel 40 feet deeper through Culebra and a way to control the Chagres, and would have taken twice as long; the lake would drown the river's floods, provide the water for the locks, and carry ships for half the crossing. Stevens, a railway builder who had found the Marias Pass for the Great Northern, saw that the canal was "a problem of transportation": the earth had to be moved, and he rebuilt the Panama Railroad with double track, brought in 100 steam shovels and 4,000 dump cars, built the towns, the mess halls and the housing for the workers before the digging began, and resigned in 1907 for reasons he never gave. Roosevelt replaced him with Colonel George Goethals of the Army Corps of Engineers, so that no one else could resign, and Goethals ran the canal until 1914 as a military commander, with a weekly open court for complaints.

The Culebra Cut

The continental divide at Culebra, later Gaillard Cut after its engineer David Gaillard, who died of a brain tumour in 1913, had to be cut 9 miles long, 300 feet wide and down to 40 feet above sea level, through a saddle 210 feet high of rock and clays that turned to soup in the rain and slid; the French had lowered it by 160 feet, and the Americans removed 96 million cubic yards more, with as many as 6,000 men in the cut at once, 100 steam shovels on terraces, 160 trains a day of spoil, dynamite by the ton, 61 million pounds in all, and a system Stevens designed in which the shovels loaded trains that ran to the dumps and returned on a loop without stopping. The slides were the enemy: the Cucaracha slide of 1907 and 1910 moved 3 million cubic yards into the cut, the banks were cut back to slopes of one in four and still slid, and the cut was not stable until the 1920s, by which time the total dug was 25 million cubic yards more than the plan; a slide closed the canal for seven months in 1915–16. Roosevelt sat on a steam shovel in the cut in November 1906, the first president to leave the country in office.

Gatun Dam and the locks

• Gatun Dam. An earth dam a mile and a half long, 100 feet high and half a mile thick at the base, built across the Chagres valley from 22 million cubic yards of spoil from the cut, with a concrete spillway; it made Gatun Lake, 164 square miles, then the largest artificial lake in the world, which drowned villages, the old railway and the jungle, and whose hilltops are the islands of Barro Colorado.
• The locks. Three lifts at Gatun on the Atlantic side, one at Pedro Miguel and two at Miraflores on the Pacific, each chamber 1,000 feet long, 110 feet wide and 41 feet deep, in pairs so that ships pass in both directions, of 4.5 million cubic yards of concrete poured from 1909 to 1913 by cableways and cranes, the largest concrete structures in the world until Hoover Dam; the gates are steel leaves 7 feet thick, 65 feet wide and up to 82 feet high, hollow so that they float, moved by electric motors, with 92 leaves in all.
• How they work. By gravity: water from the lake flows through culverts 18 feet wide in the walls and floor into the chamber to raise a ship, and out to the lower level to lower it, 52 million gallons a passage, with no pumps; electric locomotives, "mules", on rails along the walls hold the ship in the centre. A ship climbs 85 feet at Gatun in about an hour and a half, crosses the lake and the cut, and descends on the other side, 8 to 10 hours in all.
• Electricity. The canal was electric from the start, with a hydroelectric plant at Gatun and General Electric's control boards on which a model of each lock showed the operator every gate and valve, the first of their kind.

The workers and the dead

The Americans employed about 45,000 people at the peak in 1913, of whom 5,000 were Americans, skilled men on the "gold roll", paid in gold and given houses, clubs and leave, and most of the rest West Indians on the "silver roll", 20,000 from Barbados alone, recruited by the shipload, with Spaniards, Italians and Greeks in the cut, paid ten cents an hour, housed in barracks and segregated in everything from the mess halls to the post office windows. The official American count was 5,609 deaths from disease and accidents between 1904 and 1914, 4,500 of them West Indians, from malaria, pneumonia, dynamite, trains and falls; with the French dead, the canal cost about 27,500 lives, more than 500 a mile. The West Indians who stayed became a community of Panama, and their descendants' claim to recognition was met by a monument in 2017.

The opening and since

• 10 October 1913. President Wilson pressed a button in Washington that blew up the Gamboa dike and let the water into the cut.
• 15 August 1914. The steamer Ancon made the first official transit, in 9 hours and 40 minutes; the war that had begun in Europe two weeks before buried the news. The celebration was held in San Francisco in 1915.
• 1914–39. Traffic grew from 1,000 ships a year to 7,000; the Zone was a fortified American enclave, with a third set of locks begun in 1939 and abandoned in the war.
• 1964–77. Riots over the flag in 1964 killed 21; the Torrijos–Carter treaties of 1977 set the handover for 31 December 1999, which took place under President Mireya Moscoso with the Zone dissolved.
• 2007–16. Panama built a third lane of locks, 1,400 feet long and 180 feet wide, for "Neopanamax" ships of 14,000 containers, opened on 26 June 2016 at a cost of 5.4 billion dollars, with water-saving basins that reuse 60 per cent of each lockage.
• 2023–24. A drought lowered Gatun Lake and cut transits from 36 a day to 22, the first time the canal's water had failed; a new reservoir on the Río Indio is planned.

The numbers

• Length. 50 miles (82 km) from deep water to deep water; the Culebra Cut 8.5 miles; Gatun Lake 21 miles of the route.
• Lift. 85 feet (26 m) to the lake, in three locks each side; the original chambers 1,000 by 110 feet, the 2016 chambers 1,400 by 180.
• Excavation. About 240 million cubic yards in all, 60 million by the French; 96 million from the cut alone.
• Concrete. 4.5 million cubic yards in the locks and dams.
• Time. 10 years, 1904–14, opening six months early; the French 8 years.
• Cost. 352 million dollars to the United States, plus 40 million to the French company and 10 to Panama; under budget by 23 million. About 287 million lost by the French.
• Deaths. 5,609 in the American period by the official count; about 22,000 in the French; 27,500 in all.
• Traffic. About 13,000 to 14,000 transits a year, 5 per cent of world trade, 3 billion dollars a year in tolls; the largest toll about 1.2 million dollars for a cruise ship, the smallest 36 cents for Richard Halliburton, who swam it in 1928.
• Saving. 8,000 miles (13,000 km) off the New York to San Francisco voyage; three weeks off Cape Horn.

Versions and theories

• The French failed because they were incompetent. They had the best engineers of the age; they failed because a sea-level canal was the wrong plan, because nobody knew what carried yellow fever, and because de Lesseps was a promoter who would not listen to his engineers.
• The Americans dug the canal. The Americans organised it; the West Indians dug it, and died for it, with Spaniards and Italians in the cut and Chinese, Indians and Colombians from the French time.
• Roosevelt stole Panama. He encouraged the revolution, sent the Navy to stop Colombia landing troops, and signed a treaty with a Frenchman acting for a country a fortnight old; Colombia was paid 25 million dollars in 1921 by way of apology. Roosevelt's own words are the evidence.
• The canal runs west to east. Because the isthmus bends, the Pacific end is 27 miles east of the Atlantic end, and a ship crossing from the Atlantic to the Pacific sails south-east; the sun rises over the Pacific at Panama.
• The locks use pumps. No; the canal has never had a pump for lockage, and the lake's rainfall supplies the water, which is why the drought of 2023 mattered.
• Gaillard Cut is still sliding. The banks have been cut back and stabilised since the 1930s and the cut widened in 2001 to let ships pass; small slides continue and are dredged. The cut is the reason the canal has a fleet of dredges.

The other great engineering of the years before the war is in how the Brooklyn Bridge was built and the one that followed in how the Hoover Dam was built.

Open the sections: buildings by style, ancient temples of the world, all articles.