During the United War Work Campaign, he met Roy Durstine and Alex Osborn, both New York admen. The campaign the three produced was more successful even than hoped despite its timing late in the war. Later that year, Durstine and Osborn asked Barton to join them in forming a new advertising agency. Since it would allow him to continue writing for Redbook and work for himself, he agreed. In January of 1919, Barton, Durstine, and Osborn opened an office on West 54th street.Due to a case of pneumonia, Durstine was unable to run the office as planned. Barton took on the task of managing the office. Thanks in large part to the creative talents of Bruce Barton, BDO was an almost immediate success. Within five years, the agency worked with major clients such as General Electric, General Motors, Dunlop Tires, and Lever Brothers.
Despite his prominent and time consuming partnership in a hot new advertising agency, Barton continued to participate in publicity campaigns for causes in which he believed. One of the earliest examples, although unsuccessful, was clearly indicative of his belief in merging the ideals of business and religion. In the campaign for the Interchurch World Movement (IWM), a typically powerful Barton ad's headline over the image of a huge cross over the Manhattan skyline read, "We're hungry and thirsty for faith."