Ethan Allen crossed the St. Lawrence River from Longueil to Longue-Pointe on the night of September 24. Despite efforts to keep Allen’s landing a secret, word reached General Guy Carleton in Montreal, and the following day Allen was captured after a brief battle in Longue-Pointe. Allen was sent to England as a prisoner but later returned to New York City where he was exchanged for the return of Archibald Campbell, a British officer. The site of the Battle of Longue-Point is now a city park: Parc de la Capture-d'Ethan-Allen.
Range lights were established on October 28, 1903 just north of Longue-Pointe in the form of seventh-order lanterns hoisted atop poles to guide mariners safely along the St. Lawrence River at Longue-Pointe. The lights pointed roughly due south and lead through Longue-Point Traverse from the upper end of the curve at the head of Pointe aux Trembles Channel to the turn above Longue-Point Village.
The front light was shown from a six-foot-tall mast that gave the light a focal plane of thirty feet above the river, while the rear light was shown from a twenty-nine-foot-tall mast and had a focal plane of fifty-five feet. The rear light was situated 818 feet due north of the front light and was located on the south side of the main road along the shoreline.
In 1904, the mast lights were replaced by stronger lights exhibited from enclosed towers that were described in the Annual Report of the Department of Marine in 1905:
The front building stands where the front pole previously stood, on the top of the river bank, 8,825 feet N. 5° 42’ E. from Longue Pointe church. The lighthouse is a square, wooden building, with vertical sides, surmounted by an octagonal wooden lantern, the whole painted white. It is 23 feet high from its base to the ventilator on the lantern.
The light is a fixed white catoptric light, elevated 41 feet above the summer level of the river, and should be visible 4 miles in the line of range.
The back tower stands 1,013 feet due north of the front one, on the north side of the main road. It is an inclosed wooden building, square in plan, with sloping sides, surmounted by a square, wooden lantern, the whole painted white. It is 45 feet high from its base to the ventilator on the lantern.
The light is a fixed white catoptric light, elevated 65 feet above the summer level of the river, and visible 4 miles in the line of range.
This work was done by contract by Messrs. J.B. Laflamme and J.G. Howard, the contract price being $2,445.
James Fletcher was hired as the first keeper of the range lights at an annual salary of $125.
In 1927, a red, steel, skeletal tower with an enclosed wooden lantern room replaced the enclosed rear tower. This new tower increased the focal plane of the rear light from sixty-five to eighty-five feet, and it had wooden slatwork on it to enhance its visibility during the day. At the time of this change, the lights were altered from fixed white to fixed red.
Five years later, in 1932, a steel, skeletal tower with aluminum-painted slatwork on its upper portion and an aluminum-painted upper part replaced the enclosed wooden front tower. This new tower increased the focal plane of the front light from forty-one to sixty-six feet.
At some point between 1977 and 1994, the Traverse Longue-Pointe Range Lights were relocated across the river from the northern end of their axis to the southern end of their axis at Longueil. In this new location, the towers are cylindrical metal towers with enclosed lantern rooms that exhibit their lights north along the range. The front tower stands roughly twenty-nine feet tall, while the rear tower is forty-four feet tall.
Keepers: James Fletcher (1904 – 1910), Arthur Valiquette (1910 – 1921), E. Valiquette (1921 – at least 1923).