Armstrong estimated the British force at Kingston as nine hundred regulars, or two thousand men all told; and his estimate was probably correct. The usual garrison at Kingston and Prescott was about eight hundred rank-and-file. In both the British and American services, the returns of rank-and-file were the ordinary gauge of numerical force. Rank-and-file included corporals, but not sergeants or commissioned officers; and an allowance of at least ten sergeants and officers was always to be made for every hundred rank-and-file, in order to estimate the true numerical strength of an army or garrison. Unless otherwise mentioned, the return excluded also the sick and disabled. The relative force of every army was given in effectives, or rank-and-file actually present for duty.
In the distribution of British forces in Canada for 1812–1813, the garrison at Prescott was allowed three hundred and seventy-six rank-and-file, with fifty-two officers including sergeants. To Kingston three hundred and eighty-four rank-and-file were allotted, with sixty officers including sergeants. To Montreal and the positions between Prescott and the St. John’s River about five thousand rank-and-file were allotted.[159] At Prescott and Kingston, besides the regular troops, the men employed in ship-building or other labor, the sailors, and the local militia were to be reckoned as part of the garrison, and Armstrong included them all in his estimate of two thousand men.
The British force should have been known to Dearborn nearly as well as his own. No considerable movement of troops between Lower and Upper Canada could occur without his knowledge. Yet Dearborn wrote to Armstrong, March 9, 1813, from Sackett’s Harbor,[160]—
“I have not yet had the honor of a visit from Sir George Prevost. His whole force is concentrated at Kingston, probably amounting to six or seven thousand,—about three thousand of them regular troops. The ice is good, and we expect him every day.... As soon as the fall [fate?] of this place [Sackett’s Harbor] shall be decided, we shall be able to determine on other measures. If we hold this place, we will command the Lake, and be able to act in concert with the troops at Niagara.”
A few days later, March 14, Dearborn wrote again.[161]
“Sir George,” he said, had “concluded that it is too late to attack this place.... We are probably just strong enough on each side to defend, but not in sufficient force to hazard an offensive movement. The difference of attacking and being attacked, as it regards the contiguous posts of Kingston and Sackett’s Harbor, cannot be estimated at less than three or four thousand men, arising from the circumstance of militia acting merely on the defensive.”
Clearly Dearborn did not approve Armstrong’s plan, and wished to change it. In this idea he was supported, or instigated, by the naval commander on the Lake, Isaac Chauncey, a native of Connecticut, forty years of age, who entered the service in 1798 and became captain in 1806. Chauncey and Dearborn consulted together, and devised a new scheme, which Dearborn explained to Armstrong about March 20:[162]—
“To take or destroy the armed vessels at York will give us the complete command of the Lake. Commodore Chauncey can take with him ten or twelve hundred troops to be commanded by Pike; take York; from thence proceed to Niagara and attack Fort George by land and water, while the troops at Buffalo cross over and carry Forts Erie and Chippewa, and join those at Fort George; and then collect our whole force for an attack on Kingston. After the most mature deliberation the above was considered by Commodore Chauncey and myself as the most certain of ultimate success.”
Thus Dearborn and Chauncey inverted Armstrong’s plan. Instead of attacking on the St. Lawrence, they proposed to attack on the Niagara. Armstrong acquiesced. “Taking for granted,” as he did[163] on Dearborn’s assertion, “that General Prevost ... has assembled at Kingston a force of six or eight thousand men, as stated by you,” he could not require that his own plan should be pursued. “The alteration in the plan of campaign so as to make Kingston the last object instead of making it the first, would appear to be necessary, or at least proper,” he wrote to Dearborn, March 29.[164]
The scheme proposed by Dearborn and Chauncey was carried into effect by them. The contractors furnished new vessels, which gave to Chauncey for a time the control of the Lake. April 22 the troops, numbering sixteen hundred men, embarked. Armstrong insisted on only one change in the expedition, which betrayed perhaps a shade of malice, for he required Dearborn himself to command it, and Dearborn was suspected of shunning service in the field.