His earlier expressions to Seward were but arguments, without committing his Government to a line of policy, and were intended to make Seward step cautiously.
Possibly Lyons thought he could frighten the North out of a blockade campaign.

But when the Civil War actually began and Lincoln, on April 19, declared he had "deemed it advisable to set on foot a blockade," and that when a "competent force" had been posted "so as to prevent entrance and exit of vessels," warning would be given to any vessel attempting to enter or to leave a blockaded port, with endorsement on her register of such warning, followed by seizure if she again attempted to pass the blockade, Lyons felt that: "If it be carried on, with reasonable consideration for Foreign Flags, and in strict conformity with the Law of Nations, I suppose it must be recognized[505]." The Proclamation named the original seven seceding states, and on April 27 Virginia was added.

The blockade was actually begun at certain Virginia ports on April 30, and by the end of May there were a few war-ships off all the more important Southern harbours[506].

This method of putting a blockade into effect by warning at the port rather than by a general notification communicated to European governments and setting a date, involved a hardship on British merchants since they were thereby made uncertain whether goods started for a Southern port would be permitted to enter.
In practice vessels on their first departure from a blockaded harbour were warned and permitted to go out, but those seeking to enter were warned and turned back.

In _effect_, while the blockade was being established, Lincoln's Proclamation had something of the nature for the timid British merchant, though not for the bold one, of a paper blockade.