Arthur never denied that his father was Irish, he just denied the rumors that he was born in Canada.
The issue of Arthur’s father being foreign born was obscured by the Canada issue the same way that Obama’s father citizenship is also being obscured by the ‘born in Hawaii’ issue.
It was not known that Chester Arthur was born to a foreign parent at the time.
Arthur lied about his mothers time in Canada. He lied about his fathers time in Canada. He lied about his fathers age plus where and when he got off the boat from Ireland. By obscuring his parents personal history he curtailed the possibility that anybody might discover he was born many years before his father had naturalized.http://naturalborncitizen.wordpress.com/2008/12/