The National troops occupied no territory south of the Ohio, except three small garrisons along its bank and a force thrown out from Louisville to confront that at Bowling Green.

Johnston's strength was no doubt numerically inferior to that of the National troops; but this was compensated for by the advantage of being sole commander of all the Confederate forces at the West, and of operating in a country where his friends would take care of his rear without any detail of soldiers.

But when General George H.
Thomas moved upon the enemy at Mill Springs and totally routed him, inflicting a loss of some 300 killed and wounded, and forts Henry and Heiman fell into the hands of the National forces, with their armaments and about 100 prisoners, those losses seemed to dishearten the Confederate commander so much that he immediately commenced a retreat from Bowling Green on Nashville.

He reached this latter place on the 14th of February, while Donelson was still besieged.

Buell followed with a portion of the Army of the Ohio, but he had to march and did not reach the east bank of the Cumberland opposite Nashville until the 24th of the month, and then with only one division of his army.
The bridge at Nashville had been destroyed and all boats removed or disabled, so that a small garrison could have held the place against any National troops that could have been brought against it within ten days after the arrival of the force from Bowling Green.