Where does corned beef come? Why does any good Irishman say they don't eat corned beef and cabbage in the old sod? Why do we associate it with the Irish in America? It's impossible to answer these questions, but here are some ideas:
Corned beef is a wet cured product; the meat is soaked in a brine of salt and a mixture of spices. Curing meats by smoking or brining originated thousands of years ago. The 'corn' in corned beef refers to the kernels or 'kerns' of salt used in the curing process. Since this is an old Anglo-Saxon word, let's assume that the Celts of some hundreds of years ago had heard of it and used a similar process. Let's also assume that the process was used in Eastern Europe (and many other parts of the colder weather world)
The tenant farmers of Ireland, like serfs most anywhere, subsisted mainly on the root crops and other vegetables they could grow, plus bits of beef, pork and lamb not sent to the landlord. Tenants, again like other serfs, were given the less desirable cuts, hence the prevalence of sausage and sausage-like items in many peasant cuisines. The better of these lesser cuts leant themselves to curing or 'kerning' all across northern Europe, to hold them through the months ahead
If you talk to a person who has lived in Ireland he or she might grudgingly admit that yes, they do eat a cabbage and meat dish, but it's usually cabbage and bacon. The Irish-style bacon that wet-cured, or 'kerned'
Meanwhile, back in eastern and central Europe the German, Jewish and Slavic serfs were wet curing their meats. With greater access to spices from the Orient they came up with the now traditional mix of peppercorns, dill seed, coriander and a touch of garlic to liven up the finished product
Now come the great migrations of the 1800s. Immigrants from throughout Europe teamed into the eastern United States. From Baltimore to Boston the waterfronts became a Babel of languages. Nowhere else was the concentration and diversity as great as New York City. Once on the island of Manhattan, if they didn't have relatives in Brooklyn or across the Hudson in New Jersey, immigrants settled on the Lower East Side. There the melting pot was brought to a simmer. The eastern Europeans were more likely to emigrate from their homes with family and goods. Irish immigrants of the day were mostly young lads looking for work with an eye toward returning home
Here's how we see it: The eastern Europeans brought their cured meat recipes; the Irish workers brought their appetites!! 