[Yale historian Paul] Freedman says restaurants reflect American society. Delmonico’s, the first American restaurant that we would recognize as a “fine-dining” establishment, coincided with the rise of railroads, industrialization and an American aristocracy not based on nobility, but on money. And restaurants like Delmonico’s reflected the particular mores of American society, as well. In the 19th century, for example, women were allowed into restaurants only in the presence of men.
Source: America’s restaurants have evolved with American culture