2 Answers

The First Shot of the Civil War was fired on January 9, 1861, when George Edward Haynesworth, a cadet at The Citadel, fired a handgun at the Star of the West , which was attempting to reinforce Fort Sumter in Charleston Harbor . As Captain John McGowan reported, Confederate troops from Morris Island and Fort Moultrie fired 17 shots at the Star of the West, forcing it to withdraw and return to New York. President Buchanan then "reverted to a policy of inactivity that continued until he left office." Cadet Haynsworth was in the last Civil War battle east of the Mississippi and claimed to have also fired the last shot in the war. The Star of the West was later captured by the Confederates. The Citadel has a Star of the West Monument and scholarship dedicated to the cadets that fired on the ship. 

I believe it was the attack on Fort Sumter SC.

http://en.wikipedia.org/wiki/Fort_Sumter