Answer :
The correct answer is A) The American Civil War began.
What happened after seven southern states seceded from the union was the beginning of the American Civil War.
Abraham Lincoln won the elections and became President of the United States. The Southern states knew that this would be its worst nightmare. They did not support abolition because their economies depended too much on slavery. The states that seceded were South Carolina, Alabama, Mississippi, Florida, Louisiana, Georgia, and Texas. They formed the Confederate States and the War began.