Here are some of McClellan's staff-officers during the strenuous period of the Seven Days' Battles. One commonly supposes that a general's staff has little to do but wear gold lace and transmit orders. But it is their duty to multiply the eyes and ears and thinking power of the leader. Without them he could not direct the movements of his army. There were so few regular officers of ripe experience that members of the staff were invariably made regimental commanders, and frequently were compelled to divide their time between leading their troops into action and reporting to and consulting with their superior. [Illustration: THE RETROGRADE CROSSING.] [Illustration: LOWER BRIDGE ON THE CHICKAHOMINY COPYRIGHT BY PATRIOT PUB. CO.] Woodbury's Bridge on the Chickahominy. Little did General D. F. Woodbury's engineers suspect, when they built this bridge, early in June, 1862, as a means of communication between the divided wings of McClellan's army on the Chickahominy that it would be of incalculable service during battle. When the right wing, under General Fitz John Porter, was engaged on the field of Gaines' Mill against almost the entire army of Lee, across this bridge the division of General Slocum marched from its position in the trenches in front of Richmond on the south bank of the river to the support of Porter's men. The battle lasted until nightfall and then the Federal troops moved across this bridge and rejoined the main forces of the Federal army. Woodbury's engineers built several bridges across the Chickahominy, but among them all the bridge named for their commander proved to be, perhaps, the most serviceable. [Illustration: A VAIN RIDE TO SAFETY] During the retreat after Gaines' Mill, McClellan's army was straining every nerve to extricate itself and present a strong front to Lee before he could strike a telling blow at its untenable position. Wagon trains were struggling across the almost impassable White Oak Swamp, while the troops were striving to hold Savage's Station to protect the movement. Thither on flat cars were sent the wounded as we see them in the picture. The rear guard of the Army of the Potomac had hastily provided such field hospital facilities as they could. We see the camp near the railroad with the passing wagon trains in the lower picture. But attention to these wounded men was, perforce, secondary to the necessity of holding the position. Their hopes of relief from their suffering were to be blighted. Lee was about to fall upon the Federal rear guard at Savage's Station. Instead of to a haven of refuge, these men were being railroaded toward the field of carnage, where they must of necessity be left by their retreating companions. [Illustration: THE STAND AT SAVAGE'S STATION COPYRIGHT BY PATRIOT PUB. CO.]