The Union's key strategist and tactician in the West was Ulysses S. Grant, who led the Union to victories in battles at Fort Henry (February 6, 1862) and Fort Donelson (February 11 to 16, 1862), earning him the nickname of "Unconditional Surrender" Grant. With these victories, the Union gained control of the Tennessee and Cumberland Rivers. Nathan Bedford Forrest rallied nearly 4,000 Confederate troops and led them to escape across the Cumberland River. Nashville and central Tennessee fell to the Union, leading to attrition of local food supplies and livestock and a breakdown in social organization.