But Lee, safely leaving McClellan, with his great army, on the Peninsula to his inaction, swiftly gathered his army opposite Pope, and, crossing the river, advanced one wing under Jackson to strike him on the left and rear, and the other, under Longstreet, to attack him in front. Pope gained timely notice of this move by a lucky cavalry reconnoissance, and withdrew to the Rappahannock just in time to escape it. During the 17th, 18th, and 19th General Stevens kept his officers busily engaged in what he termed “looking up the country,” that is, in tracing out all the roads and by-roads, and studying the topography, defensive positions, and approaches. He always attached great importance to a thorough knowledge of the ground, and seized every opportunity to gain it. Ordered, on the afternoon of the 19th, to move back his train immediately, and his troops at two in the morning, by way of Stevensburg and Barnett’s Ford on the Rappahannock, General Stevens started off the train at once, and at nine in the evening drew out his division three miles on the designated road, which runs parallel to the river for a considerable distance, and halted. By this movement he placed his whole force in position to defend the ford till the last moment, and all danger of being cut off by the sudden advance of the enemy was obviated. The column resumed the march in retreat at two A.M., reached Stevensburg at daylight, where it was detained an hour by General Reno’s train, that officer with his division having already fallen back, and after a march of twenty-six miles crossed the Rappahannock at Barnett’s Ford, and went into bivouac at four P.M. That day the whole of Pope’s army fell back and took up the line of the Rappahannock, the ninth corps on the left.
At dusk on the evening of the 21st, leaving four companies of infantry and four light guns of the 8th Massachusetts battery at the ford, and two companies at another ford a few miles higher up, General Stevens marched eight miles up the river to Kelly’s Ford, arriving at midnight, and a day after General Reno.
The next day he recrossed the river with two brigades in support of a cavalry reconnoissance by General Buford. Deploying the third brigade,—the Highlanders and 28th Massachusetts,—he drove back a considerable force of the enemy for more than a mile in a sharp action, and, after accomplishing all that was expected or desired, withdrew to the left bank.
On the 2d both divisions continued moving up the river ten miles to Rappahannock Station, two regiments from each being left to guard Kelly’s Ford. Here were found the troops of McDowell and Banks. Sigel was farther up the river, and his artillery was heard thundering in the distance all day. Banks moved after him late in the afternoon. Both armies were now moving up the Rappahannock, but on opposite sides. Lee, foiled in his bold onslaught by the timely retreat of his antagonist, and finding him strongly posted behind the river, was now pushing his columns up the right bank, seeking to cross it or to outflank and turn Pope’s right, and Pope was carefully following his movement to head him off.
On the 23d General Stevens continued the march up the river, followed by Reno’s division. Banks’s troops and Sigel’s train were soon overtaken, blocking up the road; the march was continually interrupted and delayed by them, and after struggling forward over the muddy and slippery roads, pelted by a heavy, drenching rainstorm, until after midnight, having marched only four miles in eighteen hours, the tired and bedraggled troops were allowed to rest, or rather halt, by the roadside until morning. During the day the troops left at the lower fords rejoined the division, having been relieved by General Reynolds’s division, the first to arrive from the Army of the Potomac. On overtaking Banks’s corps, General Stevens had a talk with that officer, who was quite lame from a recent fall, and looked thin and careworn. His troops had been sadly cut up at Cedar Mountain, and his regiments, with their scanty numbers, seemed reduced almost to the size of companies. All day Sigel’s guns were thundering up the river as though a pitched battle were raging, but, as afterwards appeared, he was wasting ammunition on skirmishers and single horsemen beyond the stream, while his enormous and ill-regulated wagon-train was keeping back the rest of the army.
The march was resumed on the 24th, and Sulphur Springs reached late in the afternoon. General Stevens, riding at the head of his column, was here met by General Sigel, who requested him to take one of his (General Stevens’s) brigades and a battery, and destroy the bridge across the river at this point, which the enemy’s sharpshooters were making very hot. Astonished at such a request, a virtual acknowledgment of his own and his troops’ inefficiency, General Stevens nevertheless promptly set to work to comply with it, when the bridge was found to be in flames, having been fired by some of Sigel’s men.
On this day’s march, as the division was halting for a noon rest, and the soldiers were reclining on the ground in groups, or making their cups of coffee over little fires of fence rails, a party of rebel cavalry with a section of artillery appeared on a cross-road a mile distant and near the river, and a lively shower of shells suddenly fell over and among the resting troops. At this Lieutenant Benjamin very coolly and deliberately unlimbered and sighted one of his 20-pounders; the shell flew straight to the mark, fairly striking the annoying piece, and the enemy beat a hasty retreat at this single shot.
The following morning, the 25th, General Stevens continued marching up the river, and, on reaching Waterloo Bridge, was ordered to countermarch and proceed to Warrenton. Arrived here, passing McDowell’s corps bivouacked along the road, the division rested some hours, then marched for Warrenton Junction, and halted at midnight at a place known as Eastern View, several miles from the Junction, to which it moved the next day, the 26th.
Meantime the reinforcements were arriving from the Army of the Potomac. Reynolds’s division, 6000 strong, coming by way of Acquia Creek and the Rappahannock, joined on the 23d and was attached to McDowell’s corps. By the same route two divisions of the fifth corps, under General Fitz John Porter, reached Bealton on the 26th and the Junction the next day. They numbered 9000 effective, and were commanded by Generals George W. Morell and George Sykes respectively. On the 25th Generals Kearny’s and Hooker’s divisions of the third corps, under General Samuel P. Heintzelman, numbering 10,000 effective, were brought out on the railroad from Alexandria to the same place, Warrenton Junction. With these reinforcements, deducting losses and straggling, Pope’s strength was raised to 60,000. Lee’s army numbered,—Longstreet, 30,000; Jackson, 22,000; Stuart’s cavalry, 3000; total, 55,000.[19]
On the 22d Lee attempted a crossing near Sulphur Springs, and threw a heavy force of Jackson’s troops across the river; but the storm, and the sudden rise of the stream making the fords impassable, induced him to withdraw. Thus baffled in his design of crossing at Sulphur Springs, and finding that point and Waterloo Bridge, four miles above, held in force by the Union troops, and well knowing that Pope’s strength was increasing daily by reinforcements from the Army of the Potomac, Lee now determined to push Jackson completely around the right of the Union army, turning it by a circuitous but rapid march, and throw him on the railroad in its rear, its sole line of supply, and to follow up the movement with the other wing under Longstreet. Accordingly, on the 24th Jackson moved back from the river to Jefferson, his troops being relieved by Longstreet’s; on the 25th marched by Amissville and Orleans to Salem; and on the 26th continued his march through Thoroughfare Gap and Gainesville to Bristoe Station, on the ill-fated line of communications, which he struck at dark, capturing some prisoners and two trains loaded with supplies. Bristoe is only eight miles north of Warrenton Junction, about which so many Union troops were grouped; and Jackson, by his bold move, had thrown himself fairly upon the back of Pope’s army. Without delay he dispatched a small force that night to Manassas Junction, five miles down the railroad, and eight guns, three hundred prisoners, and an immense quantity of stores fell into his hands. Next morning, leaving Ewell to hold back the Union forces, he moved the other divisions to Manassas, where they spent the day outfitting themselves from the captured stores.