"small minority". Perhaps. But pro-Confederate Britons--pro Confederate for any number of reasons--appear to have run Britain during the US Civil War.

And many of the others appear somewhat torn. As I noted, the weaver in the "Surat" poem, had no love for either the US North or South-- realized he was just a pawn in a foreign quarrel.

Added to which, many Britons took advantage of the market--and seemed to have supplied whoever could pay. Or just filled a market niche--the US merchant marine was crippled by the astronomical insurance rates--and supposedly never recovered. Somebody took that business.