The recorded chronology of William D’Arcy’s advertising career started shortly after the turn of the century when he was one of the early members of the St. Louis Advertising Club, founded in 1901. In 1904 he was a co-founder of the Advertising Clubs of America. Later, this became the Associated Advertising Club of the World, the Advertising Federation of America, and eventually the American Advertising Federation. In August 1906 he founded the agency that still bears his name.
In 1917 D’Arcy was elected president of the Associated Advertising Clubs of the World. Elected for another term in 1918, he guided the AACW through those troubled war years, organizing a committee of advertising men who devoted their time almost exclusively to the preparation of a nationwide campaign selling 100 million people on war loans, services, contributions and work.
In an era when advertising practices left much to be desired, when the safeguards we know today did not exist for the protection of the consumer and when advertising had achieved little toward standardization or an accepted code of ethical values, D’Arcy was a prime move in the fight for truth in advertising. In 1913 D’Arcy was one of the 39-member committee who drafted the Advertising Declaration of Principles, signed and adopted at the Baltimore Convention.
D’Arcy was active in the founding of the American Association of Advertising Agencies. He served as a member of its executive board and as chairman from 1933 - 1934.
Throughout his entire career, he was staunchly dedicated to raising the status of advertising as a profession, to safeguard the interests of the consumer and advertiser alike, and to standardize media practices. He also worked to establish uniform and reliable means of measuring media values. His contributions to the field of outdoor advertising, in particular, were outstanding.