The significant historical event symbolized by the phrase "The First Shot" refers to the start of the American Civil War, specifically the first shot fired at Fort Sumter in South Carolina on April 12, 1861. This moment marked the official beginning of hostilities between the Union and Confederate forces. The fort was held by Union troops and was considered a symbol of federal authority in the seceded Southern states. The Confederate bombardment of Fort Sumter lasted for 34 hours and culminated in the surrender of the fort to Confederate forces. This event galvanized both sides and set the stage for four years of brutal conflict.