I've read a lot that Irish weren't always viewed as white in the USA and faced a lot of discrimination. Was there any distinction for protestants and/or the Ulster-Scots?

by ooeeooaaaaa

If someone was a protestant from Belfast say, who moved to the US in the 1800s or 1900s, would they have been viewed as white? Would they have faced the same anti-Irish discrimination as someone who was catholic? And what about those who were earlier descendants of Ulster-Scots people (sometimes called Scotch-Irish)? To my knowledge there were quite a few presidents of Ulster-Scots descent.

YUNoDie

To expound on this, was the anti-Irish sentiment primarily racial, or was it just a form of anti-Catholicism?