The fourth Earl of Sandwich was probably not the first person to put meat between two pieces of bread and consume it by holding it in his hand, but his doing so launched a culinary revolution that has gained momentum ever since. Sandwiches became popular in London and were first mentioned in a personal diary in 1762. Sandwich aficionados experimented with serving such different foods as ham, cheese, and shrimp in this way. Recipes for sandwiches appeared in cookbooks by the 1770s.
The British introduced sandwiches into the United States. Sandwich recipes were first published in American cookbooks in 1816. Early published sandwich fillings included oysters, potted meats, fish, poultry, cheese, crabs, lobster, prawns, and crayfish. Subsequently, sandwich ingredients expanded to include beef, minced beef, hash, pork, boiled and fried eggs, stewed fruit, chopped nuts, mushrooms, chicken, watercress, sausages, tongue, anchovies, sardines, forced meats, jelly, and jam. In 1861, a sandwich of boned fish flavored with mustard or ketchup was proposed, and five years later another author listed cheese, hard-boiled eggs, stewed fruit, jelly, and preserves as sandwich fillings.