The first official demand by the State of South Carolina, via it's governor, for Fort Sumter was made AFTER the secret attempt to re-enforce the garrison there by the Star of the West. The demand went first to Major Anderson on Jan. 11, 1861, and then to President Buchanan. Certain ex-Senators and soon to be ex-Senators representing seceding States asked that the demand by South Carolina be deferred. Although not fully happy with the agreement, the executive office of South Carolian agreed. The link below is my site showing the exchange of letters --NOT FOUND IN THE O.R.
The link... http://myathenaeum.com/simpson/page246.html
The letter that caught my eye is posted below. It suggest that Major Anderson have "supplies of food, fuel or water, and enjoy free communication, by post or special messenger, with the President, upon the understanding that the President will not send him reinforcements during the same period." This would be agreed to by Buchanan and allowed by South Carolina (and later the Confederate Government) up until April 8-9, 1861.