In which month and year did the Civil War begin?

The Civil War began in April 1861, specifically marked by the Confederate attack on Fort Sumter on April 12, 1861. This event was significant as it directly triggered the armed conflict between the Northern states (the Union) and the Southern states that seceded from the Union to form the Confederacy.

April is recognized as the official start of the Civil War due to these hostilities, which represented a culmination of escalating tensions over various issues, including states' rights and slavery. Other months mentioned in the options do not correspond with the actual start of the war; while there were earlier events and growing conflicts that led to the Civil War, the establishment of armed conflict is definitively noted as beginning in April.