The Americans, led by Major General Jacob Brown, had initially captured Fort Erie and later faced a British force commanded by Lieutenant General Gordon Drummond. The British had suffered heavy casualties at the Battle of Lundy's Lane, but Drummond aimed to drive the Americans out of the Canadian side of the Niagara River.

The siege of Fort Erie was marked by a series of unsuccessful British attacks on the American defenses. On the night of August 15/16, Drummond launched a three-pronged assault on the fort, aiming to capture American batteries and the fort itself. However, the American defenders put up a fierce resistance, causing high casualties among the British forces. The attackers faced determined opposition from American troops under General Eleazer Wheelock Ripley at Snake Hill and other fortified positions. Despite suffering heavy losses, the British were unable to breach the American defenses.

Subsequent attacks by British columns under Colonel Hercules Scott and Lieutenant Colonel William Drummond also met with significant losses, particularly during Drummond's assault on the fort, where a massive explosion of the fort's magazine caused further devastation. In total, the British suffered around 57 killed, 309 wounded, and 537 missing during the siege. The American garrison at Fort Erie reported 17 killed, 56 wounded, and 11 missing. Unknown to the Americans, Drummond had already decided to lift the siege, and the British forces withdrew on the night of September 21, citing heavy rain, illness, and lack of supplies as reasons for ending the campaign. This marked one of the last British offensives along the northern border during the War of 1812.