N. W. Ayer & Son was an advertising agency founded in Philadelphia, Pennsylvania in 1869. It called itself the oldest advertising agency in the United States. Named after Francis Ayer's father N. W. Ayer, it ventured into advertising in 1884. It created a number of memorable slogans for firms such as De Beers, AT&T and the U.S. Army. The company started to decline in the 1960s and, after a series of mergers, was closed in 2002 with its assets sold to the Publicis Groupe.