The French called it Fort Carillon, possibly after the sounds of the rapids on La Chute River, which were said to resemble the chiming bells of a carillon. Construction began in 1755 under the direction of French-Canadian military engineer Michel Chartier de Lotbiniere, cousin to the governor of New France. The site was strategically brilliant: it controlled the river portage between Lake Champlain and Lake George, the only navigable route between French Canada and the British Hudson River Valley. The Appalachian Mountains created nearly impassable terrain on either side, funneling all traffic through this chokepoint. Lotbiniere built a classic Vauban-style star fort with four bastions, walls made of squared timber packed with earth and eventually dressed in stone quarried a mile away. Inside were three barracks, four storehouses, a bakery producing 60 loaves of bread daily, and a powder magazine hacked from the bedrock beneath the Joannes bastion. General Montcalm inspected the finished fort in 1758 and criticized nearly everything about it. He failed to notice its most dangerous weakness: several nearby hills overlooked the fort, making it possible for attackers to fire down on the defenders from above.

On July 8, 1758, British General James Abercromby threw 16,000 men at the French position. He had every advantage in numbers, but his second-in-command, Brigadier General George Howe, had been killed the day before in a skirmish, and Abercromby seemed paralyzed by the loss. He chose to attack without field cannon, trusting sheer numerical superiority. It was a catastrophe. Just 4,000 French defenders, fighting from hastily built entrenchments reinforced with abatis -- felled trees with sharpened branches -- repulsed the British assault in the Battle of Carillon. The engagement happened far enough from the fort that its own cannons were barely used. Ironically, this gave Ticonderoga a reputation for impregnability that had little to do with the fort itself. The following year, General Jeffery Amherst returned with 11,000 men and emplaced artillery. The token French garrison of 400 blew up what they could and fled. The myth of the impregnable fortress, however, persisted -- with consequences that would play out two decades later during the American Revolution.

Allen and Arnold's dawn raid in May 1775 captured the fort less than a month after Lexington and Concord. The military value was immediate and enormous: Fort Ticonderoga held a substantial arsenal. Henry Knox organized one of the war's most remarkable logistical feats, hauling dozens of the fort's cannons overland through the winter mountains to Boston, where they were emplaced on Dorchester Heights. The British, suddenly staring down the barrels of guns they had stored at Ticonderoga, evacuated Boston in March 1776. The fort then served as the staging area for the American invasion of Quebec under generals Philip Schuyler and Richard Montgomery. Troops and supplies flowed through Ticonderoga for months. After the failed invasion and Montgomery's death at Quebec City, the British chased the Americans back south. The Continental Army wintered at Ticonderoga in 1776-1777 under Colonel Anthony Wayne, who reported to Washington that the fort "can never be carried, without much loss of blood." Washington, who had never visited Ticonderoga, believed the assessment.

In June 1777, General John Burgoyne led 7,800 British and Hessian troops south from Quebec, beginning the Saratoga campaign. The Americans had spent the previous year fortifying the area around Ticonderoga: trenches, batteries, a pontoon bridge to Mount Independence, a star-shaped fort on Mount Hope. But the garrison under General Arthur St. Clair numbered only 2,000 men, far too few to defend all the positions. And one critical height remained unfortified: Mount Defiance. Montcalm's engineers had missed it in 1758. The Americans knew it was a threat but lacked the troops to defend it. Burgoyne did not miss it. His troops hauled cannons to the summit of Mount Defiance, and on July 5, 1777, St. Clair ordered the fort abandoned without a fight. Washington, stunned by the news, said the event was "not apprehended, nor within the compass of my reasoning." The abandonment of the "Impregnable Bastion" sent shockwaves through the colonies, but it also set the stage for Burgoyne's overextension and eventual surrender at Saratoga four months later. The British abandoned Ticonderoga after that defeat and left it for good in 1781.

After the war, local residents stripped the fort of anything useful, even melting cannons down for metal. The ruins passed through the hands of New York State, Columbia University, and Union College before William Ferris Pell purchased the property in 1820 and turned it into a summer retreat, then a hotel as railroads brought tourists to the region. In 1848, Hudson River School artist Russell Smith painted the picturesque ruins. The Pell family hired English architect Alfred Bossom to restore the fort, opening it to the public in 1909 in ceremonies attended by President William Howard Taft, commemorating the 300th anniversary of Champlain's exploration of the lake. Stephen Hyatt Pell founded the Fort Ticonderoga Association in 1931. The British government later provided fourteen 24-pound cannons cast during the Revolution but never shipped because the war ended first. The fort earned National Historic Landmark status in 1960. Today it opens each year around May 10, the anniversary of Allen's impetuous dawn raid, and the King's Garden -- designed in 1921 by landscape architect Marian Cruger Coffin and restored in 1995 -- blooms beside the old stone walls where three empires once collided.