urces of the rebellion.
A Union army once in possession of east Tennessee would have the
inestimable advantage, found nowhere else in the South, of operating in
the midst of a friendly population, and having at hand abundant supplies
of all kinds. Mitchel had no reason to believe that Corinth would
detain the Union armies much longer than Fort Donelson had done, and was
satisfied that as soon as that position had been captured the next
movement would be eastward toward Chattanooga, thus throwing his own
division in advance. He determined, therefore, to press into the heart
of the enemy's country as far as possible, occupying strategical points
before they were adequately defended and assured of speedy and powerful
reinforcement. To this end his measures were vigorous and well chosen.

On the 8th of April, 1862,--the day after the battle of Pittsburg
Landing, of which, however, Mitchel had received no intelligence,--he
marched swiftly southward from Shelbyville, and seized Huntsville in
Alabama on the 11th of April, and then sent a detachment westward over
the Memphis and Charleston Railroad to open railway communication with
the Union army at Pittsburg Landing. Another detachment, commanded by
Mitchel in person, advanced on the same day seventy miles by rail
directly into the enemy's territory, arriving unchecked with two
thousand men within thirty miles of Chattanooga,--in two hours' time he
could now reach that point,--the most important position in the West.
Why did he not go on? The story of the railroad raid is the answer. The
night before breaking camp at Shelbyville, Mitchel sent an expedition
secretly into the heart of Georgia to cut the railroad communications of
Chattanooga to the south and east. The fortune of this attempt had a
most important bearing upon his movements, and will now be narrated.

In the employ of General Buell was a spy named James J. Andrews, who
had rendered valuable services in the first year of the war, and had
secured the full confidence of the Union commanders. In March, 1862,
Buell had sent him secretly with eight men to burn the bridges west of
Chattanooga; but the failure of expected cooeperation defeated the plan,
and Andrews, after visiting Atlanta, and inspecting the whole of the
enemy's lines in that vicinity and northward, had returned, ambitious to
make another attempt. His plans for the second raid were submitted to
Mitchel, and on the eve of the movement from Shelbyville to