I see that you're another Saul Alinsky student.
It falls apart right here, because regardless of whether the South Carolina act of secession was legal or illegal it didn't impact the ownership of Sumter. Fort Sumter was the property of the federal government, built on land deeded to the U.S. free and clear by an act of the South Carolina legislature.
The state had absolutely no legal claims to the property,
"South Carolina had ceded property in Charleston Harbor to the federal Government in 1805, upon the condition that “the United States... repair the fortifications now existing thereon or build such other forts or fortifications as may be deemed most expedient by the Executive of the United States on the same, and keep a garrison or garrisons therein” (The Statutes at Large of South Carolina [Columbia, South Carolina: A.S. Johnston, 1836], Volume V, page 501).
Work on Fort Sumter had begun in 1829 and had still not been completed by 1860. Unfinished and unoccupied for over thirty years, the terms of the cession were clearly violated and it was thus “void and of no effect.”
Consequently, the fort was never the property of the United States Government, as Lincoln claimed in his first Inaugural Address, and, upon secession from the Union, the only duty which South Carolina owed, either legally or morally, to the other States was “adequate compensation... for the value of the works and for any other advantage obtained by the one party, or loss incurred by the other” (Jefferson Davis, The Rise and Fall of the Confederate Government, Volume I, page 211). "
Oops. You've done it again.
His whole site is built on falsehood after falsehood, myth after myth.
Your entire life is built on lies and myths.
Well, no. South Carolina ceded the property on December 31, 1836 without any such qualifiers: Link
Work may not have been finished by April 1861 but it was certainly underway, with construction being performed under the supervision of an Army officer as late as December 1860 when Major Anderson transferred his command to the site. The transfer of ownership passed by the South Carolina legislature in 1836 was certainly valid, and ownership of Sumter could only be returned to the state through Congressional action. The claim that it was South Carolina's or that the troops were there illegally is flat out false.
Oops. You've done it again.
I think it's you who've done it. Again.