C, it destroyed important railroads that supplied Confederate forces.
The main reason why the colonists reacted so strongly against the tea act, which only imposed a small tax and actually lowered the price of tea, is because they felt that the decision was out of their hands, since they had no representation in British Parliament. They simply wanted to have some say in the taxation process.
After the Battle of Antietam in 1862, President Abraham Lincoln announced his intention of freeing all slaves in the Confederacy.