General Zebulon Pike landed 1700 troops to raid the town while the U.S. squadron destroyed large quantities of stores and burned a schooner under construction.

The warship then cooperated with troops attacking Fort George on 27 May, forcing a British evacuation of the Niagara Frontier.

From 7–11 August, Ontario, still with Chauncey's 13-ship squadron, fought a running engagement with British Captain James Yeo's 6-ship group.

A further sea fight on the 11th brought no more results but finally, a battle off York on 28 August succeeded in damaging two British ships and forced the enemy to flee into Burlington Bay.

Laid up in ordinary following the end of the War of 1812, the converted commercial schooner was sold on 15 May 1815 and returned to merchant service.