In January of 1862 General Ulysses S. Grant attacked Fort Henry. The Union Army came down the Tennessee River with six gunboats and 15,000 troops defeating the Confederates and taking the fort.
Next, the Union Army attacked Fort Donelson, which was only 20 miles east of Fort Henry on the Cumberland River.
At first the Confederates put up a good fight, but they were eventually defeated and forced to surrender on February 16, 1862.
Before surrendering some of the Confederates escaped including Nathan Bedford Forrest and his men. They traveled through Dickson County on their way to Nashville to warn the city that the Union Army was coming.
Less than a week later, the Union Army arrived in the Tennessee Capital to occupy the city. They would remain in control of Nashville until the end of the war.