not be held if the troops depended upon supply by wagon trains.

Grant had hardly reached Chattanooga when Halleck informed him that
it was pretty certain that Ewell's corps of 20,000 or 25,000 men had
gone from Lee's army toward East Tennessee by way of southwestern
Virginia. [Footnote: _Id_., vol. xxxi. pt. i. p. 712.] There thus
seemed to be strong confirmation of rumors which Burnside had before
reported. Before the end of the month there were also signs of a
concentration south of Loudon, and the question became a pressing
one, what line of action should be prescribed for Burnside if the
Confederates should thus attack him from both ends of the valley. He
did not credit the rumor as to Ewell's corps, but began to think
that a large detachment from Bragg's army would attack him from the
south. It is curious to find the report rife that Longstreet would
march against Burnside, even before Bragg had issued orders to that
effect. [Footnote: Official Records, vol. xxxi. pt. i. p. 718. Oct.
24.] Burnside himself proposed to take up the pontoon bridge at
Loudon, and move it to Knoxville, for both the Holston and the
Little Tennessee were now unfordable and would protect his flank
against small expeditions of the enemy. [Footnote: 2 _Id_., p. 756.]
His plan was to hold all the country he could and to concentrate at
Knoxville and stand a siege whenever the enemy should prove too
strong for him in the open field. Grant was not yet persuaded that
this was best, and wanted the line of the Hiwassee held for the
present, so that Burnside should draw nearer to Thomas rather than
increase the distance before the Cumberland army should be prepared
for active work in the field. [Footnote: _Id_., p. 770.]

Bragg's order to Longstreet to march against Burnside was issued on
the 4th of November. [Footnote: _Id_. pt. iii. p. 634.] Railway