No, but Britain fought against slavery far earlier and more effectively than other countries, including the US. It saw ridding the world of slavery as its civilising mission. There's a reason why the underground railroad went north to British territories, and why a slave of the mid 19th century would see the Union Flag as the flag of freedom much more than the Stars and Stripes, in contradiction to your statements about the USA being "way more benevolent even in its darkest years".

Britain as benevolent is so ridiculous when you know they enforced discrimination by race, i.e. segregation in many of their colonies. so lets avoid going preachy against the US please.

At least we got rid of segregation before the 1950s. Nobody is claiming that Britain is perfect, but to make out the US has some sort of moral high ground on race is ludicrous. Britain's record is a thousand times better, there.