George Bancroft, History of the United States from the Discovery of the American Continent, Vol. 8

Thomas arrived near Quebec on the first of May, and employed the next three days in ascertaining the condition of his command. He found one thousand nine hundred men, including officers. Of these, nine hundred were sick, chiefly with the small pox; out of the remaining thousand, three hundred were soldiers whose enlistments had expired on the fifteenth of April, and who refused duty, or were very importunate to return home. This small army occupied several posts so distant from each other, that not more than three hundred men could be rallied against any sudden attack. In all the magazines there remained but about one hundred and fifty pounds of powder, and six days provisions. The French inhabitants were much disaffected, so that supplies were obtained from them with great difficulty.

On the fifth, he called a council of war, who agreed unanimously to prepare for a retreat by removing the invalids immediately to Three Rivers, and embarking the cannon as soon as possible. The wise decision was made too late; that same evening ships arrived before Quebec. Early on the sixth, the Surprise frigate, the Isis, and the sloop Martin, which had forced their way up the river when it was almost impracticable from ice, came into the basin, landed their marines and that part of the twenty ninth which they had on board; and not far from noon, while the Americans were embarking their sick and their artillery, the garrison thus reinforced about one thousand strong, in two divisions, formed in columns six deep,