The American self-service grocery store was followed by the first so-called supermarkets. Early models were somewhat larger than the standard 1,000 square foot grocery and offered items at discounted prices. The idea was to make money not so much by large profits made on individual items but from smaller profits garnered by selling en masse...or on a much larger scale.

It has now been established that the nation's first supermarket opened in the Queens borough of New York City on August 4, 1930. Michael J. Cullen's 6,000 square foot King Kullen store set a new standard in the industry by establishing the discount food format, arranging items in individual departments and providing on-site automobile parking for customers.

At first, King Cullen's retail rivals -such as A & P, Kroger and Safeway- balked at the adoption of the supermarket-style store. However, a severe economic depression necessitated their acceptance of the price-based format.

New York City's King Kullen chain was another merchandising maverick of the early 20th century. Officially recognized by the Smithsonian Institution as America's first supermarket operator, the chain, headquartered in Bethpage, New York, operates stores throughout Long Island.

Graphic from http://www.kingkullen.com

King Kullen Store Number One opened in August 1930 and was located in the Jamaica neighborhood of New York City's Queens borough. The building had previously housed an auto repair garage. 

Photo from http://www.kingkullen.com