In June, Burgoyne's army of more than 7,000 regular troops embarked at St. John's, and made undisputed progress up the lake to the mouth of the Bouquet. Here it encamped on the deserted estate of William Gilliland, who had bought an immense tract in this region and made a settlement at the falls of the Bouquet in 1765, but was obliged to abandon it during the war. At this place the Indians were assembled, Iroquois and Waubanakees gathered under one banner, and alike hungry for scalps and plunder. Burgoyne addressed them in a grandiloquent speech, modeled in the supposed style of aboriginal eloquence, exhorting them to deeds of valor, to be tempered with a humanity impossible to the savages, and was briefly answered by an old chief of the Iroquois.

Moving forward to Crown Point, the army briefly rested there before advancing upon Ticonderoga. The general issued a proclamation to the inhabitants, inviting all who would to join him, and offering protection to such as remained quietly at their homes, and in no way obstructed the operations of his army, or assisted his enemies; while those who did not accept his clemency were threatened with the horrors of Indian warfare. Having delivered himself of speech and proclamation, Burgoyne continued his advance on Ticonderoga.

The post was not in the best condition for defense, as General Schuyler, now commanding the Northern Department, discovered when visiting it while Burgoyne was airing his eloquence at the Bouquet. The old French lines had been somewhat strengthened, and block-houses built on the right and left of them. More labor had been expended on the defenses of Mount Independence, a water battery erected at the fort, and another battery half way up the declivity. Communication between the forts was maintained by a bridge thrown across the lake, consisting of twenty-two piers, connected by floats fifty feet long and twenty wide. On the lower side, this bridge was protected by a boom of immense timbers fastened together by double chains of inch and a half square iron. To garrison these extensive works, General St. Clair, now the commander of Ticonderoga, had but few more than 2,500 Continental troops, and 900 poorly armed and equipped militia. He had been unwilling to call in more of the militia, for fear of a failure of supplies.

But a danger more potent than the weakness of the garrison lurked in the silent heights of Sugar Loaf Hill, now better known as Mount Defiance, that, westward from Ticonderoga, and overlooking it and all its outworks, bars the horizon with rugged steeps of rock and sharp incline of woodland. Colonel John Trumbull, of Revolutionary and artistic fame, had suggested to General Gates the advisability of fortifying it, saying that it commanded both Ticonderoga and Mount Independence. The idea was ridiculed, and he obtained leave to test the truth of his assertion. A shot from a twelve-pounder on Mount Independence struck half way up the mountain, and a six-pound shot fired from the glacis of Ticonderoga struck near the summit. Yet the Americans did not occupy it then, nor now, though a consultation was held concerning it. It was decided that there were not men enough to spare for the purpose from the fortifications already established. St. Clair hoped, moreover, that Burgoyne would choose rather to assault than besiege his position, and an assault he thought he might successfully repel.

The General Convention now sitting at Windsor sent Colonel Mead, James Mead, Ira Allen, and Captain Salisbury to consult with the commander of Ticonderoga on the defense of the frontier. While this committee was there, General Burgoyne advanced up the lake, and during his stay at Crown Point sent a force of 300, most of whom were Indians, to the mouth of Otter Creek to raid upon the settlers. The committee was refused any troops for the defense of the frontiers, but Colonel Warner was allowed to go with them, and presently raised men enough to repel this invasion.

On the 1st of July Warner wrote from Rutland to the convention that the enemy had come up the lake with seventeen or eighteen gunboats, two large ships, and other craft, and an attack was expected every hour; that he was ordered to call out the militia of Vermont, Massachusetts, and New Hampshire, to join him as soon as possible, and desired them to call out the militia on the east side of the mountain, and to send forty or fifty head of beef cattle for Ticonderoga. "I shall be glad," he writes in conclusion, "if a few hills of corn unhoed should not be a motive sufficient to detain men at home, considering the loss of such an important post might be irretrievable." In view of the impending invasion of the British, the convention appointed a day of fasting and prayer, but this pious measure had no apparent effect on the movements of the enemy, and Burgoyne continued to advance.

His army moved forward on either side of the lake, the war-craft to an anchorage just out of range of the guns of Ticonderoga and Mount Independence. The Americans abandoned and set on fire the block-houses and sawmills towards Lake George, with which the communications were now cut off.

On the 2d of July a British force of 500, commanded by Frazier, attacked and drove in the American pickets, and, the right wing moving up, took possession of Mount Hope. St. Clair expected an assault, and ordered his men to conceal themselves behind the breastworks, and reserve their fire. Frazier's force, not perceiving the position of the Americans, screened as it was by bushes, continued to advance till an American soldier fired his musket, when the whole line delivered a random volley, followed by a thunderous discharge of artillery, all without orders, and without effect but to kill one of the assailants, and raise a cloud of smoke that hung in the hot, breathless air till the assailants had escaped behind it out of range.

The possibilities of Mount Defiance had not escaped the eyes of the British engineers, and they were at once accepted. General Phillips set himself to the task of making a road up the rocky declivities, over which heavy siege guns were already being hauled. When, on the morning of the 5th of July, the sun's first rays shot far above the shadowed valley, they lighted to a ruddier glow the scarlet uniforms of a swarm of British soldiers on the bald summit, busy in the construction of a battery.

St. Clair called a council of his officers, and it was decided that it was impossible to hold the place, and the only safety of the army was in immediate evacuation. This was undertaken that night. The baggage, stores, and all the artillery that could be got away, embarked on 200 batteaux, set forth for Skenesborough under the convoy of five galleys. The main army was to march to Castleton, and thence to Skenesborough. At two o'clock on the morning of the 6th of July, St. Clair moved out of Ticonderoga. Sorrowfully the Green Mountain Boys relinquished, with almost as little bloodshed as two years before they had gained it, the fortress that guarded the frontier of their country.