...commander-in-chief of the Northern Department. He had left French Mills (Feb. 15), on the Salmon River, where the army had wintered, with most of the troops there (2,000 in number), and on reaching Sackett's Harbor received an order from the Secretary of War to march with them to the Niagara frontier, to which line Generals Scott and Ripley had already gone. The object was to recover Fort Niagara, restrain B...