Construction began in 1817 and took eight years, thousands of workers, and $7.1 million to complete. Solving engineering problems required sheer genius, and involved draining swamps, constructing aqueducts, making cement that hardened underwater, clearing forests, and building the massive locks. When finished, “Clinton’s Ditch” covered 363 miles, was about 40 feet wide and four feet deep, and rose 573 feet through a series of 83 locks. When the waterway opened, in 1825, it unlocked the floodgates to western settlement. Even though within decades it would be eclipsed by the railway, the Erie Canal was an important—and cheap—mode of transporting goods across the state for more than a century.

The canal has been enlarged several times, and today looks like a languid river. In many places it runs parallel to or completely obscures the original canal, which had towpaths on either side so mules could pull barges through the murky water. Every so often I’d spy what looked like Roman ruins made of limestone block—a bit of the old canal.

Cutting through farm fields, forests, and the outskirts of towns, the canal is used mainly by recreational boaters and state barges, and fishermen. People fish from chairs bolted to flat-bottomed bass boats, and from rickety wooden docks jutting into the water. At every opening in the lush vegetation along the shore, chairs face the water: plastic chairs, wooden chairs, Adirondack chairs, lounge chairs, kitchen chairs, and overturned buckets.

As the Cayuga sliced through the green water, spotted sandpipers ran along the stony banks. Great blue herons stood on snags and docks and took off with slow flaps when I came too close. Families of Canada geese—mother and father on either end with goslings in between—made forays into the canal. Red-tailed hawks, ospreys, and turkey vultures flew overhead. Belted kingfishers hunted from branches hanging over the water. In one four-mile stretch along Montezuma—a malarial swamp during the canal’s construction and now a national wildlife refuge—eight bald eagles, including one adult and two young birds in a nest atop a high-tension pole, considered my passing. Toward dusk, metallic-blue barn swallows with orange bellies swooped and dived in front of the boat, hunting for insects.

The Cayuga’s top cruising speed is 5.6 mph, not much more than the canal’s original speed limit of 4 mph. Each lock—and there were often several in a day’s journey—could take up to 40 minutes to navigate. Upon approach, I would radio the lockmaster and let him know whether I needed east- or westbound passage. Then I would control the Cayuga while the water rushed in or out through valves in the lock’s floor.

When given the green light, I would pull the boat into the lock, place her along the cement sidewall (a feat with a boat that acts like a bath toy because it has no keel), and grab hold of a weighted line that ran down the side of the lock—slick with ooze from the canal water and sometimes covered with zebra mussels, the scourge of the Great Lakes. Huge metal gates would slowly shut behind me, and the lock would either fill or empty. The Cayuga might rise only six feet or, in the case of the double lock at Seneca Falls, the height of a five-story building.