On April 17, Davis, since the South lacked a navy, approved a proclamation offering to issue letters of marque and reprisal.

On April 19 Lincoln proclaimed a Northern intention to treat as pirates any privateers acting under such letters, and also gave notice of a blockade of Southern ports, to be instituted later.

Thus suddenly, so it seemed to British officials and public after the long delay and uncertainty of months, events in America had precipitated a state of war, though in fact there were still to elapse other months in which both North and South laboured to transform a peaceful society into one capable of waging effective battle.
The result of this sudden change in the American horizon was to alter, almost as quickly, the previous delay in outlining a British policy, though, presumably, the British Government, while waiting the turn of events, had given careful consideration to the steps required of it in just such a situation as had now arisen.

Certainly both Lyons and Russell had been deeply anxious for some time, and had visualized a proper British policy.

The movement in Great Britain now became rapid.
On April 29, Malmesbury, in the Lords, spoke of the news of civil war which had arrived "this morning," and asked if the Government had tried to prevent it, or had set on foot negotiations with other powers to check it.