The Rebels erected batteries on the south side of the Potomac, below the Occoquan, and blockaded it. They had destroyed the Baltimore and Ohio Railroad and the Chesapeake Canal, so that the Union army and the city of Washington were dependent on the one line of railroad to Baltimore for all its supplies. It was very desirable that the Potomac should be opened. General Hooker, who commanded a division at Budd's Ferry, wished very much to attack the Rebels, with the aid of the navy, and capture the batteries, but General McClellan did not wish one division to move till the whole army was ready. December passed, and the year completed its round. Cold nights and blustering days came, and the army, numbering two hundred thousand men, went into winter quarters. CHAPTER II. BALL'S BLUFF. There were but two events of importance during the long period of inactivity in the autumn of 1861,--a disaster at Ball's Bluff and a victory at Dranesville. In October General Stone's division of the Army of the Potomac was at Poolesville in Maryland. General Banks's division was at Darnestown, between Poolesville and Washington. General McCall's division was at a little hamlet called Lewinsville, on the turnpike leading from the chain bridge to Leesburg, on the Virginia side. The main body of the Rebels was at Centreville, but there was a brigade at Leesburg. It is a beautiful and fertile country around that pleasant Virginia town. West of the town are high hills, called the Catoctin Mountains. If we were standing on their summits, and looking east, we should see the town of Leesburg at our feet. It is a place of three or four thousand inhabitants. There are several churches, a court-house, a market-place, where, before the war, the farmers sold their wheat, and corn, oats, and garden vegetables. Three miles east of the town we behold the Potomac sparkling in the sunlight, its current divided by Harrison's Island. The distance from the Virginia shore to the island is about one hundred and eighty feet; from the island to the Maryland shore it is six or seven hundred feet. The bank on the Virginia side is steep, and seventy-five or eighty feet high, and is called Ball's Bluff. A canal runs along the Maryland shore. Four miles below the island is Edward's Ferry, and three miles east of it is Poolesville. In October, General McClellan desired to make a movement which would compel General Evans, commanding the Rebels at Leesburg, to leave the place. He therefore directed General McCall to move up to Dranesville, on the Leesburg turnpike. Such a movement would threaten to cut General Evans off from Centreville. At the same time he sent word to General Stone, that if he were to make a demonstration towards Leesburg it might drive them away. On Sunday night, at sundown, October 20th, General Stone ordered Colonel Devens of the Massachusetts Fifteenth to send a squad of men across the river, to see if there were any Rebels in and around Leesburg.