Throughout the occupation of Nashville, Federal gunboats dominated the Cumberland River, making an overland attack from the south the Confederate States Army's most viable option. Late in 1862, the U.S. Army began constructing a complicated system of fortifications stretching from Hyde's Ferry to the Lebanon Pike. Fort Negley, with Blockhouse Casino and Fort Morton clustered around the Franklin Pike, protected the southern approaches to the city, including roadways and rail lines. These southern forts, connected by trenches, also created a secure pocket of free soil that attracted enslaved people from throughout the region. Although exploited as a labor force, thousands of self-emancipated men, women, and children experienced freedom for the first time on the slopes below the forts. Personal contact with former slaves convinced many soldiers to support abolition and the formation of regiments of United States Colored Troops.
