Southeast of Seven Pines was White Oak Swamp. Casey’s division of Keyes’ corps was stationed at Fair Oaks Farm. A fifth of a mile in front lay his picket line, extending crescent shape, from the swamp to the Chickahominy. Couch’s division of the same corps was at Seven Pines, with his right wing extending along the Nine Mile road to Fair Oaks Station. Heintzelman’s corps lay to the rear; Kearney’s division guarded the railroad at Savage’s Station and Hooker’s the approaches to the White Oak Swamp. This formed three lines of defense. It was a well-wooded region and at this time was in many places no more than a bog. No sooner had these positions been taken, than trees were cut to form abatis, rifle-pits were hastily dug, and redoubts for placing artillery were constructed. The picket line lay along a dense growth of woods. Through an opening in the trees, the Confederate army could be seen in force on the other side of the clearing.
The plans of the Confederate general were well matured. On Friday, May 30th, he gave orders that his army should be ready to move at daybreak.
That night the “windows of heaven seemed to have been opened” and the “fountains of the deep broken up.” The storm fell like a deluge. It was the most violent storm that had swept over that region for a generation. Throughout the night the tempest raged. The thunderbolts rolled without cessation. The sky was white with the electric flashes. The earth was thoroughly drenched. The lowlands became a morass. From mud-soaked beds the soldiers arose the next morning to battle.
Owing to the storm the Confederates did not move so early as intended. However, some of the troops were in readiness by eight o’clock. Hour after hour the forces of Longstreet and Hill awaited the sound of the signal-gun that would tell them General Huger was in his position to march. Still they waited. It was near noon before General Hill, weary of waiting, advanced to the front, preceded by a line of skirmishers, along the Williamsburg road. The Union pickets were lying at the edge of the forest. The soldiers in the pits had been under arms for several hours awaiting the attack. Suddenly there burst through the woods the soldiers of the South. A shower of bullets fell beneath the trees and the Union pickets gave way. On and on came the lines of gray in close columns. In front of the abatis had been planted a battery of four guns. General Naglee with four regiments, the Fifty-sixth and One hundredth New York and Eleventh Maine and One hundred and fourth Pennsylvania, had gone forward, and in the open field met the attacking army. The contest was a stubborn one. Naglee’s men charged with their bayonets and pressed the gray lines back again to the edge of the woods. Here they were met by a furious fire of musketry and quickly gave way, seeking the cover of the rifle-pits at Fair Oaks Farm. The Confederate infantrymen came rushing on.
But again they were held in check. In this position, for nearly three hours the Federals waged an unequal combat against three times their number. Then, suddenly a galling fire plowed in on them from the left. It came from Rains’ brigade, which had executed a flank movement. At the same time the brigade of Rodes rushed toward them. The Federals saw the hopelessness of the situation. The officers at the batteries tried to spike their guns but were killed in the attempt. Hastily falling back, five guns were left to be turned on them in their retreat. This move was not too soon. In another minute they would have been entirely surrounded and captured. The gray lines pressed on. The next stand would be made at Seven Pines, where Couch was stationed. The forces here had been weakened by sending relief to Casey. The situation of the Federals was growing critical. At the same time General Longstreet sent reënforcements to General Hill. Couch was forced out of his position toward the right in the direction of Fair Oaks Station and was thus separated from the main body of the army, then in action.
The Confederates pushed strongly against the Federal center. Heintzelman came to the rescue. The fight waged was a gallant one. For an hour and a half the lines of blue and gray surged back and forth. The Federals were gradually giving way. The left wing, alone, next to the White Oak Swamp, was holding its own.
At the same time over at Fair Oaks Station whither Couch had been forced, were new developments. He was about to strike the Confederate army on its left flank, but just when the guns were being trained, there burst across the road the troops of General G. W. Smith, who up to this time had been inactive. These men were fresh for the fight, superior in number, and soon overpowered the Northerners. It looked for a time as if the whole Union army south of the Chickahominy was doomed.
Over at Seven Pines the center of McClellan’s army was about to be routed. Now it was that General Heintzelman personally collected about eighteen hundred men, the fragments of the broken regiments, and took a decided stand at the edge of the timber. He was determined not to give way. But this alone would not nor did not save the day. To the right of this new line of battle, there was a rise of ground. From here the woods abruptly sloped to the rear. If this elevation were once secured by the Confederates, all would be lost and rout would be inevitable. The quick eye of General Keyes took in the situation. He was stationed on the left; to reach the hill would necessitate taking his men between the battle-lines. The distance was nearly eight hundred yards. Calling on a single regiment to follow he made a dash for the position. The Southern troops, divining his intention, poured a deadly volley into his ranks and likewise attempted to reach this key to the situation. The Federals gained the spot just in time. The new line was formed as a heavy mass of Confederates came upon them. The tremendous Union fire was too much for the assaulting columns, which were checked. They had forced the Federal troops back from their entrenchments a distance of two miles, but they never got farther than these woods. The river fog now came up as the evening fell and the Southern troops spent the night in the captured camps, sleeping on their arms. The Federals fell back toward the river to an entrenched camp.
Meanwhile at Fair Oaks Station the day was saved, too, in the nick of time, for the Federals. On the north side of the Chickahominy were stationed the two divisions of Sedgwick and Richardson, under command of General Sumner. Scarcely had the battle opened when McClellan at his headquarters, six miles away, heard the roar and rattle of artillery. He was sick at the time, but he ordered General Sumner to be in readiness. At this time there were four bridges across the river—two of them were Bottom’s Bridge and the railroad bridge. To go by either of these would consume too much time in case of an emergency. General Sumner had himself constructed two more bridges, lying between the others. The heavy flood of the preceding night, which was still rising, had swept one of these partially away. In order to save time, he put his men under arms and marched them to the end of the upper bridge and there waited throughout the greater part of the afternoon for orders to cross. Before them rolled a muddy and swollen stream, above whose flood was built a rude and unstable structure. From the other side could be distinctly heard the roar of battle. The fate of the day and of the Army of the Potomac rested upon these men at the end of the bridge.
The possibility of crossing was doubted by everyone, including the general himself. The bridge had been built of logs, held together and kept from drifting by the stumps of trees. Over the river proper it was suspended by ropes attached to trees, felled across the stream.