“Of all America’s enemies, the British are the ones I hate the least, and the ones I despise the most.”
The British are our enemies?
Believe it or not we fought two wars against them. A third if you count our losing the battle against the central bank.
Up until WWI, the Brits were vilified as enemies. Significant celebrations took place in NYC on the anniversary of their leaving NYC after the war; “Evacuation Day” was huge, but WWI ended it.
There were generations of Irish-Americans whose hackles were on permanent alert about any Brit, let alone relations with "those miserable murderin' black-hearts". When King George VI and wife visited in the US in 1939, it was said that a midwest city's mayor (Chicago?) threatened him if he were to visit the city.
So, yes you could say that there were times, even that recently, where the 'brotherly' feelings tended more to sibling irritation, at least for some.