My wife and I enjoyed our twice yearly trips to the US, where we were welcomed, and some welcome it was. Could be that we have only ever been to the States that were once The Confederacy. Officially The United Kingdom of Great Britain and Ireland remained neutral throughout the American Civil War. It legally recognised the belligerent status of the Confederate States of America (CSA) but never recognised it as a nation and neither signed a treaty with it nor ever exchanged ambassadors.
In the end, despite leaning toward the South in many ways, Britain never officially helped or recognised the Confederacy. Perhaps the largest reason was the institution of slavery, which was, by then, illegal in Britain.
Maybe it was our English accents, who knows, but I must say that wherever we went, wherever we dined, the welcome was just so emphatic. How I love the US, how I love Memphis.