Gee, then you'd have to wonder why the South Carolinians expended so much energy to get Ft. Sumter built.
The fact is that after the War of 1812, when the British fleet was able to bombard east coast cities more or less at will, James Madison called for the construction of a series of forts up and down the entire coast. Surveying for the entire project began in 1817, and the site for Sumter was chosen in 1826. Various legal hurdles--individuals claiming ownership of the shoal--were dealt with by the South Carolina legislature, which was eager to see the fort built. Actual work began in 1828. Oh, and during that whole time, John C. Calhoun of Charleston was either Vice President or Secretary of War.
So now the question has to be asked, where did you get YOUR education on the subject?
That’s all well and good.
But neither you nor non-sequiter answered the question. Why was the Lincoln government so intent on manning the Fort AFTER they were asked to leave ?