river and get water passage by the town. This failed, and he decided
to cross below the town and attack from the land. To aid him in this
attempt, Porter ran his gunboats past the town one night in April and
carried the army over the river. Landing on the east bank, Grant won a
victory at Port Gibson, and occupied Grand Gulf. Hearing that Johnston
was coming to help Pemberton, Grant pushed in between them, beat
Johnston at Jackson, and turning westward, drove Pemberton into
Vicksburg, and began a regular siege. For seven weeks he poured in shot
and shell day and night. To live in houses became impossible, and the
women and children took refuge in caves. Food gave out, and after every
kind of misery had been endured till it could be borne no longer,
Vicksburg was surrendered on July 4.

[Illustration: The Vicksburg Campaign]

Five days later (July 9, 1863), Port Hudson surrendered, and the
Mississippi, as Lincoln said, "flowed unvexed to the sea." It was open
from its source to its mouth, and the Confederacy was cut in two.

%444. Driving the Confederates eastward; Chickamauga and
Chattanooga%.--While Grant was besieging Vicksburg, Rosecrans by
skillful work forced Bragg to retreat from his position south of
Murfreesboro; then in a second campaign he forced Bragg to leave
Chattanooga and retire into northwestern Georgia. Bragg here received
more troops, and attacked Rosecrans in the Chickamauga valley (September
19 and 20, 1863), where was fought one of the most desperate battles of
the war. So fierce was the onset of the Confederates that the Union
right wing was driven from the field. But the left wing, under General
George H. Thomas, a grand character and a splendid officer, by some of
the best fighting ever seen held the enemy in check and saved the army
from rout. By his firmness Thomas won the name of "the Rock of
Chickamauga."

Rosecrans now went back to Chattanooga. Bragg followed, and taking
position on the hills and mountains which surround the town on the east
and south, shut in the Union army and besieged it. For a time it seemed
in danger of starvation. But Hooker was sent from Virginia with more
troops; the Army of the Tennessee under Sherman was summoned from
Vicksburg; Rosecrans was superseded by Thomas, and Grant was put in
command of all. Then matters changed. The forces under Thomas, moving
from their lines, seized some low hills at the foot of Missionary Ridge,
east of Chattanooga (November 23). O