If I am not mistaken, and correct me if I am, I read somewhere that more territory changed hands, in regards to tactical control, because of the fall of these forts than any where else during the War.

That the Union offensive against Forts Henry and Donelson caused the Confederates to have to abandon the entire state of Kentucky and middle Tennessee, including Nashville the Tennessee state capitol, withdrawing all the way to northern Mississippi before Johnston was able to muster his forces for an offensive against Grant at Shiloh.

Many people tend to forget that during 1861 and the winter of 1862 the Confederate Army occupied much of eastern (Confederate)Kentucky to the Ohio River.