American cheese is a type of processed cheese. It can be orange, yellow, or white in color, is mild, salty, and faintly sweet in flavor, has a medium-firm consistency, and has a very low melting point.
Very early in its history, American cheese was only white in color—as it was made from a blend of cheeses (most often including cheddar cheese) which were originally only white. However, the later versions are often a yellow hue due to the addition of annatto, a sweet and nutty seasoning added to cheddar and to Colby so that by the late 1800s American cheese was often simply called "yellow cheese."
Today’s American cheese is, by law, required to be manufactured from at least two types of cheese. Because its manufacturing process differs from "unprocessed"/raw/natural cheeses, American cheese can not be legally sold under the name (authentic) "cheese" in the US. Instead, federal (and even some state) laws mandate that it be labeled as "processed cheese" if simply made from combining more than one cheese, or "cheese food" if dairy ingredients such as cream, milk, skim milk, buttermilk, cheese whey, or albumin from cheese whey are added. As a result, sometimes even the word "cheese" is absent altogether from the product's labeling in favor of, e.g., "American slices" or "American singles". In the United Kingdom, packs of individually wrapped slices are labeled as "singles", although they are commonly referred to as "cheese slices".
The marketing term, "American Cheese", for processed cheese—combined with the ubiquitous prevalence of processed cheeses in the US, versus outside it—has led to the terms American cheese and "processed cheese" being used interchangeably in America. However, the term "American cheese" has a legal definition as a type of pasteurized processed cheese under the American Code of Federal Regulations.
British colonists made cheddar cheese soon upon their arrival in North America. By 1790, American cheddars were being exported back to England. According to Robert Carlton Brown, author of The Complete Book of Cheese, "The English called our imitation Yankee, or American, Cheddar, while here at home it was popularly known as yellow or store cheese". In 1878, the total export of American cheese was 355 million pounds per year, with an expected growth to 1,420 million pounds.