Palmerston was reluctant to ask Parliament for the funds to send an entire army to North America. While London awaited a response, the British geared up for war. On 29 November, therefore, Palmerston sent an ultimatum to Washington demanding the release of Ambassador Slidell and Mason, disavowal of Captain Wilkes’ actions, and an apology. The Crown’s legal offices eventually decided that, while the interception of Trent was probably legal, boarding her certainly was not. In fact, given past British insistence on the rights of belligerents to intercept neutrals (an American casus belli in 1812, when it declared war on Great Britain over British violations of US maritime rights), Palmerston might have had no choice but to accept the action. The Palmerston government, however, was not at first so bellicose. Ambassador Lyons reported from Washington that the American press was positively gloating at the violation of British sovereignty. Image: Wikimedia Commons/Library of Congress. An American party went aboard and found two Confederate ambassadors there, thus beginning the crisis known as the Trent Affair. USS San Jacinto (on the right) stopping British steamer RMS Trent, 8 November 1861.

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