First (from History.com):
"Corned Beef
Each year, thousands of Irish Americans gather with their loved ones on St. Patrick's Day to share a "traditional" meal of corned beef and cabbage.
Though cabbage has long been an Irish food, corned beef only began to be associated with St. Patrick's Day at the turn of the century.
Irish immigrants living on New York City's Lower East Side substituted corned beef for their traditional dish of Irish bacon to save money. They learned about the cheaper alternative from their Jewish neighbors."
Corned beef was produced in Ireland (after British "Landlords" brought cattle to the island) but was primarily an export item since the Irish couldn't afford it.
My paternal grandparents, Irish natives, had (eventually) a small neighborhood grocery store at 107th and Amsterdam in NYC – two doors down from a Jewish Deli. Beef was more plentiful in The States and therefore less expensive. Cabbage was still a staple, and "Corned Beef and Cabbage" was born!
I will be joining my son and a friend of his for our annual dinner (a 20 year tradition) at a local restaurant owned by an Irish family where they (grudgingly) serve up a shyte load of corned beef, cabbage, potatoes and soda bread.
Fortunately they got a liquor license just about the time me boyo was old enough to drink. No more O'Doul's. Now we can savor Guinness, Harp or Smithwick's.