rather than supporting them as you said.

What I said was that they invaded Mexico, which they did. And I said that to correct your false statement that the British were more worried about Napoleon III than anything that happened on the other side of the ocean.

Internal US affairs become relevant to the world when the US becomes a major world player, which is WWI and not before,

The only reason you're saying this is because you don't know about the parts of your history that you're unaware of. Workers in England were willing to starve to support the Union in the American Civil War. Does that sound like America had "minimal influence" on British politics?

How could a country to which millions upon millions of you are immigrating have a minimal influence on your politics?

The workers supported the Union because they recognized that it was their fight. It was the same reason tens of thousands of Britons volunteered for the Union Army. If you don't believe me, read their speeches.

The fact is that anything and everything having to do with America has simply been written out of your history. You don't even learn about our revolution. Or the 170 years of British history in North America that preceded it. It's a sad state of affairs.