This section is from the book "The American Woman's Cook Book", by Ruth Berolzheimer. Also available from Amazon: The Domestic Arts Edition of the American Woman's Cook Book.
AN encyclopedia published about 1900 defines a sandwich as "an article of food consisting of a slice of meat, fish, fowl or other food placed between two slices of bread, which may be plain or buttered." No such simple definition could be given today, for from these simple beginnings the sandwich has developed in all directions, and has adapted itself to such varied needs that it ranges from a fragile morsel served with afternoon tea to an elaborate combination of toast, meat, lettuce, tomato, sauce, and any number of other things which combine to make it a complete and satisfying meal.
Even the requirement of two slices of bread with something between them is no longer in force. "Open-faced" sandwiches offer almost unlimited opportunity for variety in both cold and hot meals. In these the slices of bread or toast are laid side by side. Sometimes, usually in hot meat sandwiches, both slices are covered with beef or chicken, or whatever gives the characteristic flavor, and the whole is covered with gravy. Often, especially in cold sandwiches, one slice holds its chicken or tomato or crab meat, while its companion is covered with cole slaw and dill pickles or a lettuce leaf holding a spoonful of mayonnaise. The possibilities are endless, and the suggestions given here can be combined and adapted to almost any requirement where a sandwich can be called into service.