Answer:
The first shots were fired by Confederate forces in Fort Sumter, North Carolina. Tensions had been rising, and this was the first act of war that triggered the armed conflict.
Step-by-step explanation:
A big difference existed between the northern and southerns states throughout the 19th century American growth. The northerners had established a manufacturing industry (and small-scale farming too), but the south based their whole large-scale farming system on the labor of black slaves.
Abolitionist sentiment began to grow in the north and it was important to discuss what was to happen with the new territories of the west. The election of Lincoln (1860) was the final straw (because of his abolitionist posture), and after that South Carolina, Mississippi, Florida, Alabama, Georgia, Louisiana and Texas left the Union. After the Fort Sumter battle, Virginia, Arkansas, North Carolina and Tennessee joined the other states and thus began the war.