<P> A serious diplomatic dispute with the United States erupted over the "Trent Affair" in late 1861 . Public opinion in the Union called for war against Britain, but Lincoln gave in and sent back the diplomats his Navy had illegally seized . </P> <P> British financiers built and operated most of the blockade runners, spending hundreds of millions of pounds on them; but that was legal and not the cause of serious tension . They were staffed by sailors and officers on leave from the Royal Navy . When the U.S. Navy captured one of the fast blockade runners, it sold the ship and cargo as prize money for the American sailors, then released the crew . </P> <P> A long - term issue was the British shipyard (John Laird and Sons) building two warships for the Confederacy, including the CSS Alabama, over vehement protests from the United States . The controversy was resolved after the Civil War in the form of the Alabama Claims, in which the United States finally was given $15.5 million in arbitration by an international tribunal for damages caused by British - built warships . </P> <P> In the end, these instances of British involvement neither shifted the outcome of the war nor provoked either side into war . The U.S. diplomatic mission headed by Minister Charles Francis Adams, Sr. proved much more successful than the Confederate missions, which were never officially recognized . </P>

What policy had the united states followed regarding other countries