I only have a passing understanding of the potato famine. Been to Ireland, and there's a couple of variations on the history. What I've gotten from is was that, obviously, England wasn't responsible for the famine itself. But the taxation on fertile land, and the policies they had of sending food to England, regardless of the need in Ireland, made the problem MUCH worse than it could have been. In my understanding, taxation on the land in the East, which is very fertile, became prohibitive. Many farmers went to the west coast, where, if you've been there, you know how harsh it is. Potatoes (underground crops) grew well there. That became the major crop. blight (plant disease) hit, and the crops went sour. No food. Now, there were still a lot of farming of other crops done in other areas, but from my understanding, much was shipped to the UK.
Others, I'm sure, will clarify further or better.
Yes, that is basically my understanding of the potato famine, also. My question was for Shutupandtakeit. He/she seems to think there was a different cause and I was interested in knowing what he/she thought it was.