"Fort Donelson will hereafter be marked in Capitals on the maps of our United Country..." Brigadier General Ulysses S. Grant was becoming quite famous as he wrote these words following the surrender of Confederate Fort Donelson on Sunday, February 16, 1862. The Union victory at Fort Donelson elated the North, and stunned the South. Within days of the surrender, Clarksville and Nashville would fall into Union hands. Grant and his troops had created a pathway to victory for the Union.

...Excerpt from NPS website