The initial reaction in the United States was to rally against Britain, threatening war; but President Abraham Lincoln and his top advisors did not want to risk war. In the Confederate States, the hope was that the incident would lead to a permanent rupture in Anglo-American relations and even diplomatic recognition by Britain of the Confederacy. Confederates realized their independence potentially depended on a war between Britain and the U.S. In Britain, the public expressed outrage at this violation of neutral rights and insult to their national honor. The British government demanded an apology and the release of the prisoners while it took steps to strengthen its military forces in Canada and the Atlantic.
After several weeks of tension and loose talk of war, the crisis was resolved when the Lincoln administration released the envoys and disavowed Captain Wilkes's actions. No formal apology was issued. Mason and Slidell resumed their voyage to Britain but failed in their goal of achieving diplomatic recognition.
The Confederate “ambassador” to the Court of St. James’s never even met formally with the Prime Minister or the Foreign Secretary. He later gave up in disgust and returned to Richmond, as did the legate to the French court. While the latter had been received more cordially, a dreaded alliance between the French and the Confederacy never emerged.