I can't answer these questions, but consider the following. Everyone knows about the Irish and the potato. And everyone knows about the huge Irish migration to New York City. And "potatoes O'Brien" is found on New York City menus around 1900.
2 April 1905, New York Times, pg. X7:
10 October 1909, New York Times, pg. X5:
A favorite dish of one New York chef is potatoes O'Brien. It is nothing more than cold boiled potatoes fried with finely-shaped red or green pepper mixed through them.
4 October 1910, Chicago Daily Tribune, pg. 8:
HOW and when the honor came to O'Brien of having his name in special attached to a potato dish is probably told in some of the many charming books on Celtic life and literature. We know something of the story of how a vegetable of American origin came to be called the Irish potato, but how it came to have added to it a tropical condiment and then to be named after one of the great Irishmen, is not so well known.