Twice Cumberland Gap was seized by the Rebels, and twice was it wrested away from them.

In 1861 it was the point whence Zollicoffer launched out with his legions to "liberate Kentucky," and it was whither they fled, beaten and shattered, after the disasters of Wild Cat and Mill Springs.

In 1862 Kirby Smith led his army through the Gap on his way to overrun Kentucky and invade the North.

Three months later his beaten forces sought refuge from their pursuers behind its impregnable fortifications.

Another year saw Burnside burst through the Gap with a conquering force and redeem loyal East Tennessee from its Rebel oppressors.
Had the South ever been able to separate from the North the boundary would have been established along this line.
Between the main ridge upon which Cumberland Gap is situated, and the next range on the southeast which runs parallel with it, is a narrow, long, very fruitful valley, walled in on either side for a hundred miles by tall mountains as a City street is by high buildings.