...? Yes, I know corn referred to a mix of grains. In fact, in the UK, where I and the other people posting on this thread live, 'corn' is still a generic word for grain.

I believe that it is largely in the USA that the word 'corn' is used to mean maize, and maize only? We say 'maize' in general food manufacture, or as flour, or 'sweet corn' for the tinned stuff or fresh cobs.

Of course none of that helped the Irish. They had no money at all, and no potatoes, so it didn't help that much that the repeal of the Corn Laws applied to lots of different grains!