Corned Beef and Cabbage
Corned beef is a beef brisket soaked in brine (with some sugar and spices). According to "The Joy of Cooking," corned beef "has nothing to do with corn but got its name...when a granular salt the size of a kernel of wheat -- corn to a Briton -- was used to process it.".
This has a reputation of being an Irish dinner. Corned beef came into the picture as a lower-cost substitution, to replace the more expensive and harder to find cut.
But, why "corned beef"? New York's early immigrant populations lived in very crowded neighborhoods, and there was a close proximity between the Irish and Jewish communities. Evidence of its legacy is apparent in numerous cultures, including Ancient Europe and the Middle East.
The Jewish population produced similar koshered cured beef product made from the brisket which the Irish immigrants purchased as corned beef from Jewish butchers.