On January 13, 1813, John Armstrong Jr. was appointed United States Secretary of War. Having been a serving soldier, he quickly appreciated the situation on Lake Ontario, and devised a plan by which a force of 7,000 regular soldiers would be concentrated at Sackett's Harbor on April 1. Working together with Chauncey's squadron, this force would capture Kingston before the Saint Lawrence River thawed and substantial British reinforcements could arrive in Upper Canada. The capture of Kingston and the destruction of the Kingston Royal Naval Dockyard together with most of the vessels of the Provincial Marine, would make almost every British post west of Kingston vulnerable if not untenable. After Kingston was captured, the Americans would then capture the British positions at York and Fort George, at the mouth of the Niagara River.