On the third day of November 1775, Brig. Gen. Richard Montgomery and his Continental army triumphantly concluded a taxing two-month siege with the surrender of British Fort St. Johns and its 600-man garrison. Their invasion of Canada had finally gained momentum. A week later, the Continentals assembled on the south shore of the St. Lawrence, ready to cross the river and take their next objective, Montreal.
British Governor Guy Carleton had already recognized that Montreal was not tenable. On Thursday, November 7, he ordered his last 150 British regular soldiers, government officials, prominent Loyalists, gunpowder stores, and other military supplies to be loaded aboard eleven sailing ships: the brig HMS Gaspée, armed provincial schooners Isabella, Maria, Polly, and La Providence, transport schooner Reine des Anges, sloops Brilliant and St. Antoine, and three smaller, unidentified sailing vessels. The governor and his deputy, Brig. Gen. Richard Prescott, embarked on Gaspée to lead the mass evacuation downriver (northeast) to Quebec City.
Once the ships were loaded, however, prevailing winds blew directly from the northeast for several days, hindering departure and making “every British heart tremble” over their fate. The act of sailing a ship directly into the wind on the St. Lawrence was risky—even with the one or two knot current. It required tacking through narrow channels with the risk of grounding on shallows, or having one’s ship stuck vulnerably “in irons,” with no wind in the sails to maneuver.
On Saturday afternoon, November 11, the days of waiting came to an end as flags and weathervanes turned under a cold northwest wind, with snow flurries. Around three o’clock, a single cannon signaled the governor’s flotilla to weigh anchor and set sails for the 170-mile river voyage to Quebec City. The British and Canadian Loyalists fled in the nick of time—Montgomery and his advance guard marched victoriously into Montreal just two days later.
On the first full day underway, the challenges of sailing ships on the river became readily apparent—one of the armed schooners ran aground on a shoal, just a short distance downstream from Montreal. The crew took hours to free the ship and get back underway. Carleton’s eleven ships had only put thirty miles between them and Montreal that day before the winds shifted northeast again. “The elements seemed to conspire” against their timely escape. The fleet sat in anchorage off the north shore parish of Lavaltrie for two days, waiting until advantageous winds returned on Tuesday, November 14. The ships resumed their trip downriver, but only managed to sail another dozen miles before contrary winds, “very violent with heavy snow,” returned that evening. The fleet anchored a few miles short of Sorel, a fifty-dwelling town at the confluence of the Richelieu River.