The J. Walter Thompson Company, one of the largest advertising agencies in the U.S. (and around the world), is also the oldest one still in existence. Founded in 1864 in New York, it was by the late 19th century already one of the most innovative companies, a leader in moving toward providing "full service" advertising and marketing for its clients. The "house ads" in this category illustrate how the JWT Company promoted its name and its work at a time when using an outside advertising agency was not routinely assumed to be part of doing business.