James Russell Soley, Professor U. S. Navy, Confederate Military History, a library of Confederate States Military History: Volume 7.1, The blockade and the cruisers
Clement Anselm Evans, Ed.

[31] neutral, especially after the blockade was proclaimed, as blockade is a purely belligerent act. Her offence, reduced to its exact proportions, consisted in taking the ground of a neutral before the magnitude and force of the insurrection were such as to justify it. But the hopes raised at the South by the proclamation led to the prevalent belief throughout the Union that it was dictated by unfriendly motives; while the undisguised sympathy for the Southern cause shown by the upper classes in England tended to strengthen the impression and to aggravate the wound.

The inception of the blockade was somewhat irregular. Ordinarily a blockade may begin in one of two ways; either by a public announcement coupled with the presence of a force before the blockaded port; or by stationing the force without an announcement. The first is a blockade by notification; the second is a blockade in fact. As breach of blockade only becomes an offence when accompanied by knowledge, actual or constructive, of the existence of the blockade, it is a question of some importance when the blockade begins and how knowledge of it is to be acquired. In a blockade by notification, knowledge is held to have been acquired when sufficient time has elapsed for the notice to have been generally received; and after this time a neutral vessel, by sailing for the blockaded port, has committed an offence and incurred a penalty. With a blockade that is purely de facto, on the other hand, knowledge must be obtained on the station, and neutrals have a right to sail for the port and to be warned off on their arrival.

Whether a blockade is initiated as a blockade by notification or as a blockade de facto, the indispensable condition of its establishment is the presence of a force at the blockaded port. Actual notice of the fact can never precede the