the operation and the siege-works embraced both
cities, Petersburg was the vital and vulnerable point. When Petersburg
fell, Richmond fell of necessity. The reason was, that Lee's army,
inclosed within the combined fortifications, could only be fed by the
use of three railroads centering at Petersburg; one from the southeast,
one from the south, and one with general access from the southwest.
Between these, two plank roads added a partial means of supply. Thus
far, Grant's active campaign, though failing to destroy Lee's army, had
nevertheless driven it into Richmond, and obviously his next step was
either to dislodge it, or compel it to surrender.

Cold Harbor was about ten miles from Richmond, and that city was
inclosed on the Washington side by two circles of fortifications devised
with the best engineering skill. On June 13, Grant threw forward an army
corps across the Chickahominy, deceiving Lee into the belief that he was
making a real direct advance upon the city; and so skilfully concealed
his intention that by midnight of the sixteenth he had moved the whole
Union army with its artillery and trains about twenty miles directly
south and across the James River, on a pontoon bridge over two thousand
feet long, to City Point. General Butler, with an expedition from
Fortress Monroe, moving early in May, had been ordered to capture
Petersburg; and though he failed in this, he had nevertheless seized and
held City Point, and Grant thus effected an immediate junction with
Butler's force of thirty-two thousand. Butler's second attempt to seize
Petersburg while Grant was marching to join him also failed, and Grant,
unwilling to make any needless sacrifice, now limited his operations to
the processes of a regular siege.

This involved a complete change of method. The campaign against
Richmond, from the crossing of the Rapidan and battle of the Wilderness,
to Cold Harbor, and the change of base to City Point, occupied a period
of about six weeks of almost constant swift marching and hard fighting.
The siege of Petersburg was destined to involve more than nine months of
mingled engineering and fighting. The Confederate army forming the
combined garrisons of Richmond and Petersburg numbered about seventy
thousand. The army under Grant, though in its six weeks' campaign it had
lost over sixty thousand in killed, wounded, and missing, was again
raised by the reinforcements sent to it, and by its junction with
Butler, to a tot