What is the significance of Fort Sumter?

Fort Sumter, located in Charleston, South Carolina was one
of two federal ports in the southern United States. Soon after the election of 1860
seven southern states succeeded from the Union.  President Lincoln declared that the
Union would hold on to these two ports after the succession.  However, on April 10, 1861
the Confederate General Beauregard demanded evacuation of the post by the Union troops. 
When they refused General Beauregard attacked Fort Sumter on April 12, 1861.  On April
13, 1861, Fort Sumter was captured by the Confederacy and on April 14, 1861 Major Robert
Anderson surrendered to the Confederacy. 

In response to
the capture of Fort Sumter, President Lincoln called on state militias to put down the
rebellion.  This in turn caused more states to join the Confederacy. The battle for
control of Fort Sumter marked the beginning of what was to become the Civil
War.