During the American Civil War, the county was part of the battlegrounds, occupied repeatedly by more than 100,000 troops for several years. In 1862, before and after the Battle of Fredericksburg, some 10,000 African-American slaves left area plantations and city households to cross the Rappahannock River, reaching the Union lines and gaining freedom. This exodus and Trail of Freedom is commemorated by historical markers on both sides of the river, in Fredericksburg and in Stafford County. The Battle of Aquia Creek took place in the Aquia Harbour area. Both the Union Army and Confederate Army struggled to control the strategic Potomac Creek Bridge at various times during the war.