Caples was one of advertising's most influential copywriters. After graduation from the Naval Academy at Annapolis, Caples began his advertising career at Ruthrauff & Ryan in 1925, during the decade in which advertising began to assume its modern form, both in style and organizational structure. In 1927, Caples moved to Batten, Barton, Durstine & Osborne (BBDO), to work alongside Bruce Barton, an advertising legend and pioneer of direct mail. Remained at BBDO 55 years, and reshaped the field of direct response advertising.
At BBDO Caples was an influential copywriter, widely published author, and legend in advertising industry. Elected: New York Copywriters Hall of Fame (1974); American Advertising Federation Hall of Fame (1977). Since 1977 the John Caples Award has been given by the Direct Marketing Creative Guild as "symbol of personal creative excellence in direct marketing." His books are considered classics, widely reprinted and translated.