the country. McClellan, as
general-in-chief, gave his approval, suggesting a modification in
regard to the column to move from the Big-Sandy valley. His
information led him to believe that the Big-Sandy River could be
relied upon as navigable to Prestonburg, which was seventy miles
from Abingdon by what was supposed to be a good road. He thought,
therefore, that it would be easier to make Prestonburg the base and
to use wagons. [Footnote: O, R., vol. v. p. 722.] On investigation
Rosecrans reported that the most feasible route in that region was
by steamboat transportation to Pikeville, twenty-five miles above
Prestonburg, in the Big-Sandy valley, and thence up the Louisa Fork
of the Big-Sandy by way of Pound Gap to the Holston valley; but
there would still be eighty-eight miles of marching after leaving
the steamboats, and navigation on the Big-Sandy was limited to brief
and infrequent periods of high water.

On the 12th of March he submitted his modified plan to the
adjutant-general of the army. [Footnote: _Id_., p. 744.] It had
grown more complex with the passage of time. The eastern line of the
department had been moved forward so as to bring the South Branch of
the Potomac and the Cow-pasture branch of the James River under
Rosecrans's command. He now planned four separate columns. The first
was to move up the south branch of the Potomac with a view to turn
and to capture the enemy's position at Alleghany Summit or Monterey
on the Staunton turnpike. The second and third were to be in my
district, and to move toward the Virginia and Tennessee Railroad on
the two sides of New River. The fourth should march from the
Big-Sandy valley on the line indicated above. Rosecrans seems to
have limited his plan to the occupation of the mountain valleys as
far east as the Blue Ridge, and did not submit any scheme for
uniting his columns for further work. He asked for reinforcements to
the extent of six regiments of infantry, one of cavalry, and two
field batteries to enable him to perform his task. The use of pack
trains was given up, as they required a greater number of animals
than could be procured. In fact, it was never found to be an
economical use of mule power, and important movements were always
confined to lines upon which wheel vehicles could be used. A rapid
cavalry raid could be thus supplied, but heavy columns of infantry
and artillery demanded wagon trains.

The weakness of Rosecrans's scheme is found in the wid