See also the ship's log of the USS Supply. The link goes to the official records. The Union forces started landing near Fort Pickens during the night of April 11, 1861 before shots were fired at Fort Sumter on April 12, 1861.
LINKUSS SUPPLY -- SHIPS LOG - APRIL 11, 1861
April 7. -- Came to anchor in the harbor of Pensacola.
April 11. -- At 9 p. m. the Brooklyn got Underway and stood in toward the harbor, and during the night landed the troops and marines on board, to reenforce Fort Pickens.
Your spam posts do not shed any useful light on this discussion. Here are records of the United States sending soldiers of the United States Army to reinforce forts belonging to the United States. I spoke of the aggression of South Carolina in attacking said forts. Given the bellicose Confederate actions in beginning the war, it is little wonder that the United States suspected that it should reinforce its property. By the Confederate reasoning, the United States begins a war with Cuba every time it sends naval forces to its own base there.