Did the South in firing on Fort Sumter begin the war?
No. Various hostile acts had been committed before this took place. The first hostile act was committed by the Federal government when Major Robert Anderson secretly removed his garrison at night from Fort Moultrie, a weak fort in Charleston harbor, to Fort Sumter, a very strong fort. Shortly after, the government, under James Buchanan, sent the Star of the West with troops and supplies to Fort Sumter, but she was driven off. If South Carolina had a right to secede, she had a right to all the public buildings upon her territory, saving her responsibility for the cost of construction, which she readily recognized. She took over Fort Moultrie and other buildings and she was joined by other Southern States. Nevertheless no one was hurt, there was no war, and Virginia interposed with her Peace Conference, originated and presided over by John Tyler.
After Lincoln came in, the peace apparently continued for four or five weeks, but secretly Lincoln took means to bring on war.. Despite the assurances of Seward, the Secretary of State, assurances made with Lincoln's full knowledge,* that the status would not be disturbed at Fort Pickens, and in violation of a truce existing there between the Federals and Confederates, Lincoln sent secret orders for the landing of troops, but Adams, the Federal commander of the squadron before Fort Pickens, refused to land the troops, declaring that it would be a breach of faith to do so, and that it would bring on war. This was before Sumter was fired on, and Fort Sumter was fired on only when an armed squadron, prepared, also with great secrecy, was dispatched with troops to supply that fort also.
But firing upon Fort Sumter did not in any case necessarily mean war. No one was hurt by the firing, and Lincoln knew that all the Confederates wanted was a fort that commanded the Metropolitan city of South Carolina - a fort which had been erected for the defense of that city. He knew that they had no desire to engage in a war with the United States. Not every hostile act justifies war, and in the World War this country submitted to having its flag filled full of holes and scores of its citizens destroyed before it went to war. Lincoln, without any violation of his views of government, had an obvious alternative in putting the question of war up to Congress, which could have been called in ten days. But he did not do it, and assumed the powers of Congress in making laws, besides enforcing them as an executive. By his mere authority he enormously increased the Federal army, marched it to the South, blockaded Southern ports, and declared Southern privateersmen pirates. Every clause of Jefferson's tremendous indictment against King George in 1776 was true of Lincoln in 1861-1865.