Most of those installations they "seized" were not even garrisoned. Fort Pulaski for instance...and others.
Most others, the south paid for and evacuated the troops peacefully.
Lincoln knew that attempting to resupply and reinforce ft. sumter...which was in charleston harbor...the first state to secede...would be an intolerable provocation.
He wanted war and he needed a casus belli. He saw an opportunity to provoke it iat ft. sumter...which was not even part of the u.s. at this point as they had peacefully seceded. He even admitted it;
"You and I both anticipated that the cause of the country would be advanced by making the attempt to provision Fort Sumter, even if it should fail ; and it is no small consolation now to feel that our anticipation is justified by the result. "
Abraham Lincoln, in a letter to Gustavus Fox, May 1, 1861
Major anderson was told to refuse to evacuate peacefully as lincoln sent ships and troops...to what was now a sovereign foreign nation, the CSA.
beauregard knew that the best way to prevent the invasion was to take the fort.
No one was killed and the troops were peacefully evacuated back to the north after they surrendered...but he had his excuse to attack and murder civilians, steal fellow americans property, wreck their homes and businesses, cripple the infrastructure and deprive them of their rights...because they wanted to PEACEFULLY and LEGALLY withdraw from the union...
He also admits the war was about tariffs and taxes and not about slavery.
"But what am I to do in the meantime with those men at Montgomery [meaning the Confederate constitutional convention]? Am I to let them go on... [a]nd open Charleston, etc., as ports of entry, with their ten-percent tariff. What, then, would become of my tariff?" ~ Lincoln to Colonel John B. Baldwin, deputized by the Virginian Commissioners to determine whether Lincoln would use force, April 4, 1861.
Many saw through the northern tactic to provoke a war;
"The affair at Fort Sumter, it seems to us, has been planned as a means by which the war feeling at the North should be intensified, and the administration thus receive popular support for its policy.... If the armament which lay outside the harbor, while the fort was being battered to pieces [the US ship The Harriet Lane, and seven other reinforcement ships], had been designed for the relief of Major Anderson, it certainly would have made a show of fulfilling its mission. But it seems plain to us that no such design was had. The administration, virtually, to use a homely illustration, stood at Sumter like a boy with a chip on his shoulder, daring his antagonist to knock it off. The Carolinians have knocked off the chip. War is inaugurated, and the design of the administration accomplished." ~ The Buffalo Daily Courier, April 16, 1861.
"We have no doubt, and all the circumstances prove, that it was a cunningly devised scheme, contrived with all due attention to scenic display and intended to arouse, and, if possible, exasperate the northern people against the South.... We venture to say a more gigantic conspiracy against the principles of human liberty and freedom has never been concocted. Who but a fiend could have thought of sacrificing the gallant Major Anderson and his little band in order to carry out a political game? Yet there he was compelled to stand for thirty-six hours amid a torrent of fire and shell, while the fleet sent to assist him, coolly looked at his flag of distress and moved not to his assistance! Why did they not? Perhaps the archives in Washington will yet tell the tale of this strange proceeding.... Pause then, and consider before you endorse these mad men who are now, under pretense of preserving the Union, doing the very thing that must forever divide it." ~ The New York Evening Day-Book, April 17, 1861.
The rest of the world was watching, too..It was obvious.
"Union means so many millions a year lost to the South; secession means the loss of the same millions to the North. The love of money is the root of this as of many other evils....The quarrel between the North and South is, as it stands, solely a fiscal quarrel".... Charles Dickens in a London periodical in December 1861
"The contest is really for empire on the side of the North and for independence on that of the South....". ..... London Times of 7 Nov 1861
"Slavery is not the cause of the rebellion ....Slavery is the pretext on which the leaders of the rebellion rely, 'to fire the Southern Heart' and through which the greatest degree of unanimity can be produced....Mr. Calhoun, after finding that the South could not be brought into sufficient unanimity by a clamor about the tariff, selected slavery as the better subject for agitation"..... North American Review (Boston October 1862)
"They [the South] know that it is their import trade that draws from the people's pockets sixty or seventy millions of dollars per annum, in the shape of duties, to be expended mainly in the North, and in the protection and encouragement of Northern interests....These are the reasons why these people [the North] do not wish the South to secede from the Union." ..... New Orleans Daily Crescent 21 January 1861
"In one single blow our foreign commerce must be reduced to less than one-half what it now is. Our coastwise trade would pass into other hands. One-half of our shipping would lie idle at our wharves. We should lose our trade with the South, with all of its immense profits. Our manufactories would be in utter ruins. Let the South adopt the free-trade system, or that of a tariff for revenue, and these results would likely follow." .... Chicago Daily Times December 1860
"At once shut down every Southern port, destroy its commerce and bring utter ruin on the Confederate States." ..... NY Times 22 March 1861
"the mask has been thrown off and it is apparent that the people of the principal seceding states are now for commercial independence. They dream that the centres of traffic can be changed from Northern to Southern ports....by a revenue system verging on free trade...." .... Boston Transcript 18 March 1861
He couldn't have cared less about slaves...he said so himself.
"My paramount object in this struggle is to save the Union, and is not either to save or to destroy slavery. If I could save the Union without freeing any slave I would do it, and if I could save it by freeing all the slaves I would do it; and if I could save it by freeing some and leaving others alone I would also do that. What I do about slavery, and the colored race, I do because I believe it helps to save the Union."
-- Abraham Lincoln
-From, Letter to Horace Greeley
August 22, 1862
"Negro equality! Fudge!! How long, in the government of a God great enough to make and maintain this Universe, shall there continue knave to vend, and fools to gulp, so low a piece of demagoguism as this?"
-- Abraham Lincoln
-From, Fragments: Notes for Speeches
Sept. 1859 (Vol. III)
"But what shall we do with the Negroes after they are free? I believe that it would be better to export them all to some fertile country with a good climate, which they could have to themselves."
-- Abraham Lincoln
-From, Letter to General Benjamin F. Butler
March 1865 (Vol. VII)
"I will say then that I am not, nor ever have been in favor of bringing about in any way the social and political equality of the white and black races, (applause from audience) that I am not nor ever have been in favor of making voters or jurors of Negroes, nor of qualifying them to hold office, nor to intermarry with white people. I will say in addition to this that there is a physical difference between the white and black races which I believe will forever forbid the two races living together on terms of social and political equality. And inasmuch as they cannot so live, while they do remain together there must be the position of superior and inferior, and I as much as any other man am in favor of having the superior position assigned to the white race."
-- Abraham Lincoln
-From, 4th Debate with Stephan A. Douglas in Illinois
Sept. 1858 (Vol. III)
"Judge Douglas has said to you that he has not been able to get an answer out of me to the question whether I am in favor of Negro citizenship. So far as I know, the Judge never asked me the question before. (applause from audience) He shall have no occasion to ever ask it again, for I tell him very frankly that I am not in favor of Negro citizenship. (renewed applause) If the state of Illinois has the power to grant Negroes citizenship, I shall be opposed to it. (cries of "here, here" and "good, good" from audience) That is all I have to say."
-- Abraham Lincoln
-From, Speech at Sringfield, Illinois
June 1857 (Vol. II)
"In the course of his reply, the Senator remarked that he had always considered this a government made for the white people and not for the Negroes. Why, in point of mere fact, I think so, too."
-- Abraham Lincoln
-From, Speech at Peoria, Illinois
Oct. 1854 (Vol. II)
"I think your race suffers very greatly, many of them by living among us, while ours suffers from your presence. In a word we suffer on each side. If this is admitted, it affords a reason why we should at least be separated."
-- Abraham Lincoln
-From, Address on Colonization to a Deputation of
Africans in Washington D.C.
August 1862 (Vol. V)
The lying bastard couldn't even tell the truth in his inaugural address;
Apprehension seems to exist among the people of the Southern States that by the accession of a Republican Administration their property and their peace and personal security are to be endangered. There has never been any reasonable cause for such apprehension. Indeed, the most ample evidence to the contrary has all the while existed and been open to their inspection. It is found in nearly all the published speeches of him who now addresses you. I do but quote from one of those speeches when I declare that—
I have no purpose, directly or indirectly, to interfere with the institution of slavery in the States where it exists. I believe I have no lawful right to do so, and I have no inclination to do so.
Those who nominated and elected me did so with full knowledge that I had made this and many similar declarations and had never recanted them; and more than this, they placed in the platform for my acceptance, and as a law to themselves and to me, the clear and emphatic resolution which I now read:
Resolved, That the maintenance inviolate of the rights of the States, and especially the right of each State to order and control its own domestic institutions according to its own judgment exclusively, is essential to that balance of power on which the perfection and endurance of our political fabric depend; and we denounce the lawless invasion by armed force of the soil of any State or Territory, no matter what pretext, as among the gravest of crimes.