McDowell, however, has no idea that the Enemy will stand still to let this thing be done. On the contrary, he is well satisfied that Beauregard will accept battle on some chosen ground between Manassas Junction and Washington. On the afternoon of Tuesday, the 16th of July, the advance of McDowell's Army commences. That Army is organized into five divisions--four of which accompany McDowell, while a fifth is left to protect the defensive works of Washington, on the South bank of the Potomac. This latter, the Fourth Division, commanded by Brigadier-General Theodore Runyon, comprises eight unbrigaded New Jersey regiments of (three months, and three years) volunteers--none of which take part in the ensuing conflicts-at-arms. The moving column consists of the First Division, commanded by Brigadier-General Daniel Tyler, comprising four brigades, respectively under Brigadier-General R. C. Schenck, and Colonels E. D. Keyes, W. T. Sherman, and I. B. Richardson; the Second Division, commanded by Colonel David Hunter, comprising two brigades, under Colonels Andrew Porter and A. E. Burnside respectively; the Third Division, commanded by Colonel S. P. Heintzelman, comprising three brigades, under Colonels W. B. Franklin, O. B. Wilcox, and O. O. Howard, respectively; and the Fifth Division, commanded by Colonel Dixon S. Miles, comprising two brigades, under Colonels Lewis Blenker, and Thomas A. Davies, respectively. Tyler's Division leads the advance, moving along the Leesburg road to Vienna, on our right, with orders to cross sharply to its left, upon Fairfax Court House, the following (Wednesday) morning. Miles's Division follows the turnpike road to Annandale, and then moves, by the Braddock road,--along which Braddock, a century before, had marched his doomed army to disaster,--upon Fairfax Court House, then known to be held by Bonham's Rebel Brigade of South Carolinians. Hunter follows Miles, to Annandale, and thence advances direct upon Fairfax, by the turnpike road--McDowell's idea being to bag Bonham's Brigade, if possible, by a simultaneous attack on the front and both flanks. But the advance is too slow, and the Enemy's outposts, both there and elsewhere, have ample opportunity of falling safely back upon their main position, behind the stream of Bull Run. [McDowell in his testimony before the "Committee on the Conduct of the War," said: "At Fairfax Court House was the South Carolina Brigade. And I do not suppose anything would have had a greater cheering effect upon the troops, and perhaps upon the Country, than the capture of that brigade. And if General Tyler could have got down there any time in the forenoon instead of in the afternoon, the capture of that brigade was beyond question. It was about 5,000 or 6,000 men, and Tyler had 12,000, at the same time that we were pressing on in front. He did not get down there until in the afternoon; none of us got forward in time."]