The great expansion of business in the 19th century was accompanied by the growth of an advertising industry; it was that century, primarily in the United States, that saw the establishment of advertising agencies. The first agencies were, in essence, brokers for space in newspapers. But by the early 20th century agencies became involved in producing the advertising message itself, including copy and artwork, and by the 1920s agencies had come into being that could plan and execute complete advertising campaigns, from initial research to copy preparation to placement in various media.
