Kentucky was a border state of key importance in the American Civil War. President Abraham Lincoln recognized the importance of the Commonwealth when he declared "I hope to have God on my side, but I must have Kentucky." In a September 1861 letter to Orville Browning, Lincoln wrote:

I think to lose Kentucky is nearly the same as to lose the whole game. Kentucky gone, we cannot hold Missouri, nor Maryland. These all against us, and the job on our hands is too large for us. We would as well consent to separation at once, including the surrender of this capitol.