Which of these two countries have the closest relations with the U.S.A; The Republic of Ireland or the UK?

When did England suddenly become the UK? I think Scotland and the USA have a far closer relationship due to their shared history. They both wanted independence from England - and the USA managed to do it first - with a lot of Scottish inspiration. Scotland is still trying to get their independence. Maybe the USA will be kind enough to support them in their efforts some day? lol