The march was delayed by deep snow and mud, and he was not able to occupy Odelltown until 30 March, and begin the attack on Lacolle Mill until the early afternoon. The Americans opened fire with two 12-pounder cannon and a 5.5 inch mortar. They could not bring an 18-pounder gun into action because of soft ground around the area. The British garrison fired back with their Congreve rockets. Although the rockets were inaccurate, they caused several American casualties. The American troops had not encountered these weapons before in battle and were unnerved. The flank (i.e. the Light and Grenadier) companies of the 13th had been stationed nearby. They launched a bayonet charge against the American artillery emplacements, but they were far outnumbered and were repulsed. Hearing the firing from some away, a company of the Canadian Voltigeurs and the Grenadier company of the Canadian Regiment of Fencible Infantry also marched to reinforce the defenders. They waded through icy water to slip through the American lines and opened fire on American artillery, wounding the American artillery commander, his replacement and many of the gun crews. The Americans were also under fire from British gunboats under Commander Daniel Pring of the Royal Navy, who had brought his vessels up the Richelieu River from Ile aux Noix to the mouth of the Lacolle River. By evening, the Americans had made little impression on the British defences. Rather than launch an all-out assault, Wilkinson ordered a retreat. The Americans returned to Plattsburgh, considerably disheartened. Wilkinson had recklessly exposed himself to British fire throughout the action, though to little purpose. On 11 April, Wilkinson received orders from Armstrong relieving him of command. This was probably not a direct result of the debacle at Lacolle Mills, but followed a request made by Wilkinson himself on 24 March for a Court of Enquiry to rule on his conduct of the St. Lawrence campaign the previous year. This eventually resulted in a court martial, but Wilkinson was acquitted of various charges of negligence and misconduct. The failure nevertheless allowed Armstrong to promote a crop of comparatively junior officers to command divisions and brigades. Major General George Izard, who had been on leave when the Battle of Lacolle Mills was fought, eventually took command at Plattsburgh. Thirteen active regular infantry battalions of the United States Army (1-2 Inf, 2-2 Inf, 1-3 Inf, 2-3 Inf, 4-3 Inf, 1-4 Inf, 2-4 Inf, 3-4 Inf, 1-5 Inf, 2-5 Inf, 1-6 Inf, 2-6 Inf and 4-6 Inf) perpetuate the lineages of a number of American units (the old 5th, 6th, 11th, 13th, 14th and 20th Infantry Regiments) that were present at the battle.