During the fall and winter of 1860-61, the Southern leaders committed many acts of treasonable aggression. They seized United States property, acting under the authority of their States, until the formation of the Confederacy, when the central government became their authority. In some of these cases the Federal custodians of the property yielded it in recognition of the right of the State to take it. In some cases they abandoned it, hopeless of being able to hold it against the armed forces that threatened it, and doubtful of support from the Buchanan Administration at Washington. But there were noble exceptions, and brave officers held to their trusts, and either preserved them to the United States Government or released them only when overpowered. In December, 1860, the rebels seized Castle Pinckney and {10} Fort Moultrie in Charleston Harbor, the arsenal at Charleston, and the revenue cutter _William Aiken_; in January, the arsenals at Mount Vernon, Ala., Apalachicola, Fla., Baton Rouge, La., Augusta, Ga., and many forts, hospitals, etc., in Southern ports. By February they had gained such assurance of not being molested in their seizures of Government property, that everything within their reach was taken with impunity. So many of the officers in active service were in sympathy with the South, that it frequently required only a demand for the surrender of a vessel or a fort--sometimes not even that--to secure it. One of these attempted seizures gave rise to an official utterance that did much to cheer the Northern heart. John A. Dix, who in January, 1861, succeeded Cobb as Secretary of the Treasury, sent W. H. Jones, a Treasury clerk, to New Orleans, to save to the Government certain revenue cutters in Southern ports. Jones telegraphed the secretary that the captain of the cutter _McClelland_ refused to give her up, and Dix thereupon sent the following memorable despatch: "Tell Lieutenant Caldwell to arrest Captain Breshwood, assume command of the cutter, and obey the order I gave through you. If Captain Breshwood, after arrest, undertakes to interfere with the command of the cutter, tell Lieutenant Caldwell to consider him as a mutineer and treat him accordingly. If any one attempts to haul down the American flag, shoot him on the spot." These determined words were among the few that were uttered by Northern officials that gave the friends of the Union any hope of leadership against the aggression of the seceding States; and they passed among the proverbial expressions of the war, to live as long as American history. [Illustration: A SUMTER CASEMATE DURING THE BOMBARDMENT.] The firmness of Lieutenant Adam J. Slemmer had prevented the surrender of Fort Pickens, in Pensacola Harbor, Florida, on the Gulf of Mexico, when it was demanded with some show of force, in January, 1861.