In 1809, when President Thomas Jefferson reviewed New York’s ambitious plans for a more than 360-mile canal connecting the Hudson River (and therefore New York Harbor) to the Great Lakes, he dismissed it as “little short of madness” and refused to authorize federal funding. Less than a decade later, when New York’s politically savvy governor DeWitt Clinton pushed the controversial canal plan through the state legislature, opponents mocked the project as “DeWitt’s Ditch” and “Clinton’s Folly.”

Yet in 1825, just eight years after workers broke ground, DeWitt boarded a barge called the Seneca Chief and took a victory cruise along the newly opened Erie Canal, an engineering marvel, unlike anything America had ever seen. The man-made waterway, designed by untrained engineers, featured 83 separate locks, two massive stone-and-cement aqueducts to crisscross the Mohawk River, and a final ingenious “flight” of interconnected locks to raise boats over the 70-foot Niagara Escarpment.

The Erie Canal was built decades before the invention of dynamite to efficiently blast through stubborn rock, or steam-powered earth-movers and excavators to clear mud, rock and rubble. Instead, the thickly forested land was cleared and the 40-foot wide canal was dug and the locks were constructed by the raw manpower of an estimated 50,000 laborers, including a large contingent of recently arrived Irish immigrants.

“The Erie Canal was the first major infrastructure project in the history of America,” says Derrick Pratt, museum educator at the Erie Canal Museum. But the first challenge to building the Erie Canal was that the United States didn’t have a single college of engineering or any native-born engineers.

“They tried to hire European engineers, but they were either too busy, too expensive or didn’t want any part of this audacious scheme to cut through what was wilderness at the time to get from the Hudson River to the Great Lakes,” says Pratt.

So the Canal Commissioners had no choice but to hire an amateur crew of self-taught local engineers that included a few inexperienced surveyors and at least one local math teacher. The two chief engineers were Benjamin Wright and James Geddes, lawyers by trade who learned how to survey by prosecuting land disputes.

Wright sent his assistant, a young man named Canvass White, to spend a year in England to learn everything he could about locks, the brilliant method first conceived by Leonardo Da Vinci for raising and lowering boats to accommodate changes in elevation.

Returning to America, White helped make a key discovery. Lock construction, as well as aqueducts, required something called hydraulic cement, a type of masonry mortar that hardened and remained stiff underwater. But the only hydraulic cement at the time came from Europe and was wildly expensive to ship. After some experimentation, White and a colleague named Andrew Barstow identified a local source of limestone that when properly pulverized and burned, produced a lime that could be used to make hydraulic cement cheaply and abundantly.

The men who rose to engineering positions on the Erie Canal—including some who began the project with an axe in their hands clearing trees—became known as graduates of the “Erie School of Engineering” and lent their hard-won expertise to the next century of American expansion and innovation. An actual school of engineering, now the Rensselaer Polytechnic Institute, was founded in 1824 in Troy, New York, right alongside the Erie Canal.

Ground was broken for the Erie Canal on July 4, 1817, just outside Rome, New York. Work commenced with the 90-mile middle section of the canal where there were the fewest natural impediments like rocky cliffs or swamps. Setting a precedent for future public works projects, the Canal Commissioners contracted out the construction work to local landowners, who were responsible for hiring the laborers to dig the canal to the engineer’s specifications: a slant-sided “prism” of water 40 feet wide and four feet deep, with towpaths on either side.

At first, the contractors mostly hired local farmers and homesteaders who were eager to get this new waterway completed and have ready access to lucrative markets up and down the canal. Wages were 50 cents to a dollar a day and the work in those first years was painfully slow. From 1818 to 1819, around three thousand men and 700 horses labored every day to dig the section of the Erie Canal from Utica to the Seneca River.

According to an 1820 report from the Canal Commission, three-quarters of these early laborers were “born among us.” But those demographics changed quickly when work on the canal moved westward into a soggy and mosquito-plagued region called the Montezuma swamps. Unable to convince upstate farmers to muck it out in the inhospitable territory, contractors hired teams of Irish immigrants freshly arrived in New York Harbor. Thousands of Irish laborers were sickened or died in the swamps from what was called “Genesee fever,” but which was actually malaria.

Irish immigrant labor gradually overtook local workers and anti-Irish, anti-Catholic sentiment swelled along the canal construction route. The Irish workers were often paid in whiskey in addition to (or sometimes in place of) their meager wages of $12 a month. While brawling and skirmishes with locals were a frequent problem, the Irish workers proved willing to do the dirtiest and most dangerous work, including blasting rock with unpredictable black powder.

Historian Gerard Koeppel, author of Bond of Union: Building the Erie Canal and the American Empire, quotes the lyrics of a popular Irish work song: "We are digging a ditch through the mire, Through the mud and the slime and the mire, dammit! And the mud is our principal hire; In our pants, down our boots, down our necks, dammit!"

Much of the planned route for the Erie Canal ran through thickly forested wilderness and the early teams of laborers had nothing more than axes, pickaxes and shovels to fell countless trees and uproot giant stumps. In time, the canal’s amateur engineers devised brilliant contraptions to make the work dramatically faster.

The first was a crank-driven tree feller adapted from European designs. A cable was tied to the top of a large tree and connected to an “endless screw” that was ratcheted and cranked by men, horses or oxen until the tree was ripped from the ground, roots and all.

Another device was invented by Nathan Roberts, a local math teacher who became one of the Erie Canal’s most storied engineers. Some trees were too small to be yanked down with the ratchet and had to be cut, leaving their stubborn stumps. Roberts designed a giant stump remover with 16-foot wheels that could be powered by a team of oxen to pull 40 stumps a day compared to only four a day using conventional labor.

Farm implements were repurposed and redesigned to help with the monumental task of digging the hundreds of miles of canal. An implement called a “plow and scraper” was pulled through the earth by draft horses to break up small roots and loosen tough clay. Another device called a “slip scraper” functioned like a modern-day bulldozer or bucket loader, scraping up rubble and dumping it into debris piles.

But perhaps the simplest and most lasting innovation was conceived by Jeremiah Brainard, a canal contractor who made a small fortune selling his patented “Brainard’s barrow” to workers frustrated with the old style of the wheelbarrow that was box-shaped with vertical sides. Brainard’s design had a rounded basin that made it far easier to dump out the wheelbarrow’s contents with one good heave.

The final section of the Erie Canal posed the greatest challenge of all. The Niagara Escarpment, the same elevated rock formation that created the Niagara Falls, blocked access to Lake Erie.

“The canal engineers had to figure out how to overcome this 70-foot change in elevation,” says Pratt of the Erie Canal Museum. “The average lock on the canal could only lift between 10 and 15 feet.”

There was a competition to come up with the best solution and Nathan Roberts, a former schoolteacher, came up with the winning idea: a “staircase” of five consecutive locks, each stacked on top of the other. The “flight” of locks was so successful that the nearby town was named Lockport, but the challenge wasn’t over.

To provide enough water to fill those locks, a massive channel needed to be dug through solid bedrock to reach Lake Erie. Twelve hundred mostly Irish workers blasted through seven miles of rock with dangerous black powder. They also built raging fires to heat the rock, which could then be cracked with a sudden douse of cold water. Special tower cranes were built to remove the endless piles of rubble and dozens of workers died or were severely injured by exploding rock and falling debris.

Plied with whiskey by avaricious contractors, the Irish got a bad reputation in Lockport, which was the site of a violent riot in 1822 between Northern Irish Protestants and Southern Irish Catholics. But after the so-called “Deep Cut” through the rock was completed, many of the Irish workers settled in Lockport and established a proudly Irish outpost in Upstate New York.

The Erie Canal, fully completed in 1825, was an immediate triumph, transporting goods, people and ideas between the East Coast and the frontier settlements of the Midwest and beyond. In 1834, the canal underwent a major enlargement—70 feet wide and seven feet deep—to better handle an increased crush of boat traffic.