t at Columbus, on
the Mississippi. Defensive earthworks had already been begun at Fort
Donelson, on the left Bank of the Cumberland, Fort Henry, on the right
bank of the Tennessee, twelve miles west of Fort Donelson, and at
Columbus, on the Mississippi. General Johnston, with the aid of his
engineers, Lieutenant Dixon and Major J.F. Gilmer, afterward General and
Chief Engineer of the Confederate army, adopted these sites as places to
be strongly fortified. The line from Columbus to Bowling Green became
the line chosen to bar access from the North to the South, and to serve
as a base for invasion of the North.

The idea of breaking this line by an expedition up the Tennessee and
Cumberland Rivers seems to have presented itself to many. Colonel
Charles Whittlesy, of the Twentieth Ohio, a graduate of West Point and
formerly in the army, while acting as Chief Engineer on the staff of
General O.M. Mitchell in Cincinnati, wrote to General Halleck, November
20, 1861, suggesting a great movement by land and water up the
Cumberland and Tennessee Rivers, on the ground that this was the most
feasible route into Tennessee, and would necessitate the evacuation of
Columbus and the retreat of Buckner from Bowling Green. In December,
1861, General Sherman, conversing with General Halleck, in St. Louis,
suggested that the proper place to break the line was the centre, to
which Halleck assented, pointing on the map to the Tennessee River, and
saying that is the true line of operations. On January 3, 1862, General
D.C. Buell, in a letter to General Halleck, proposed a combined attack
on the centre and flanks of General Johnston's line, and added: "The
attack on the centre should be made by two gunboat expeditions, with, I
should say, 20,000 men on the two rivers." General Halleck, writing to
General McClellan, January 20, 1862, said a movement down the
Mississippi was premature; that a more feasible plan was to move up the
Cumberland and Tennessee, making Nashville the objective point, which
movement would threaten Columbus and force the abandonment of Bowling
Green, adding "but the plan should not be attempted without a large
force--not less than 60,000 men." General McClellan, however, thought
such a movement should be postponed for the present. He wrote on January
6th, to General Buell, Commander of the Department of the Ohio, which
department included all of Kentucky east of the Cumberland River: "My
own general plans for the prosecut