Fort Sumter is primarily important for the following reason:
- It marked the beginning of the war.
The attack on Fort Sumter on April 12, 1861, by Confederate forces is widely recognized as the official start of the American Civil War. While it did contain Union weapons, the significance lies in its role as the catalyst for the conflict between the North and the South. The other options do not accurately capture the primary importance of Fort Sumter in the context of the Civil War.