...lan was, by means of a steamer (a single one), then in our possession, to throw troops across the lower Potomac, for a partial campaign, against a Federal force said to be on the opposite bank, under General Sickles . Mr. Davis had evidently forgotten that the Potomac, at that point, was more than a mile and a half wide; with a tide rising and falling from five to six feet, twice in twenty-four hours; with sh...