Until the late nineteenth century, delicatessens were primarily run by Germans and Alsatians in this country. The word itself derives from German and means delicacies, but is used not only to describe a shop, but is also the word for the products sold in a shop. Eventually, Jews too went into the business.
Delis were especially attractive for the observant as the stores were open on Sundays, selling canned and packaged goods, often duplicating the services of grocery stores.
More than anything else the delicatessen became the "Jewish eating experience" in this country. The quintessential Jewish "kosher style" delicatessen today is the Carnegie on Fifty-fifth and Seventh Avenue in New York. It was here that the deli became known nationwide when New York magazine rated its pastrami number one in New York in 1975.
Carnegie Deli in NY
Nate n' Al's Deli in LA