In the United States, the Department of Agriculture (USDA) and the Food and Drug Administration (FDA) are the responsible agencies for protecting the definition of sandwich.

[4] However, the same USDA manual determines that burritos and fajitas are "sandwich-like" and frankfurters are "sandwich type", while stromboli is explicitly excluded.

The bread is frequently coated with condiments such as mayonnaise or mustard to enhance its flavour and texture, but may be served plain ("dry").

[10] The use of some kind of bread or bread-like substance to lie under some other food, or to scoop it up and enclose or wrap it, is found in many cultures historically.

[11] Flat breads of only slightly varying kinds have long been used to scoop or wrap small amounts of food en route from platter to mouth throughout Western Asia and northern Africa.

The immediate culinary precursor with a direct connection to the English sandwich was to be found in the Netherlands of the seventeenth century, where the naturalist John Ray observed[13][14] that in the taverns beef hung from the rafters "which they cut into thin slices and eat with bread and butter laying the slices upon the butter"—explanatory specifications that reveal the Dutch belegde broodje, open-faced sandwich, was as yet unfamiliar in England.

Initially perceived as food that men shared while gaming and drinking at night, the sandwich slowly began appearing in polite society as a late-night meal among the aristocracy.

[8][9] It is commonly said that Lord Sandwich, during long sessions of cribbage and other card games at public gambling houses, would order his valet to bring him roast beef between two pieces of toasted bread.

The sandwich's popularity in Spain and England increased dramatically during the nineteenth century, when the rise of industrial society and the working classes made fast, portable, and inexpensive meals essential.

By the early 20th century, as bread became a staple of the American diet, the sandwich became the same kind of popular, quick meal as was already widespread in the Mediterranean.

The court further ruled that such a definition of sandwich would also apply to a "restaurant that serves made-to-order Greek gyros, Indian naan wraps, or Vietnamese banh mi".

Similar usage applies in other Spanish-speaking cultures, such as Mexico, where the word torta is also used for a popular variety of roll-type sandwiches.

In 1979, the British store chain Marks & Spencer introduced a small range of chilled, pre-made sandwiches sold in wedge-shaped boxes, sealed to keep them fresh.