Corned beef's origin goes back to the Middle Ages. The word 'corned' is from Old English for granules or salt.
The best is slowly and well-cured in spiced brine.

English, Irish, American, all developed from the same roots and goes well with cabbage and other greens and vegetables.

Irish corned beef was important in food for the British Navy from the 17th to the 19th centuries, and for general use in British Isles and America. Poor grades were sold to the French and used in their colonies.
Dublin, Belfast and other cities in Ireland had large beef curing and packing industries.

It was an English, Irish and American dish. See Wikipedia and other references.

Ham with cabbage is now prepared everywhere. Dunno when it became more popular than beef in cured meat use with cabbage.