It sounds like an interesting thing to look up. One thing you might want to remember though is that some in Europe, Irish and Scots particularly, get a kick out of winding up guys from America who look a bit gullible and inquire about some connection they have to someone’s country. You’d be surprised how many times I’ve heard Oh you’re from Scotland, do you know Kenneth/Hamish/Calum/etc?” and it is genuinely tempting to say “Yes” and make something silly up.
So just mentally prepare yourself that this could end up being the punchline of a joke that was originally told 100 years back :-)
Oh no doubt but, and no offence to the English intended, I think the number of Americans who will proudly say "I'm a quarter English!" is miniscule compared to those claiming the same for Irish or Scottish and I haven't heard anyone claiming Welsh heritage personally (despite there being a decent number of American Jones-es)
So just mentally prepare yourself that this could end up being the punchline of a joke that was originally told 100 years back :-)