All three of those "First Fathers" were born in Ulster!
No other US Presidents could claim closer connections to their ancestral homeland.
Those three Presidents were:
Andrew Jackson. His father was born in Carrickfergus, Co. Antrim
James Buchanan. His father was born in Ramelton, Co. Donegal
Chester Alan Arthur. His father was born in Cullybackey, Co. Antrim
At least 17 US Presidents have Ulster-Scots ancestry.