I looked through the Library of Congress and found some old photos of the "Federal Advertising Agency," which may or may not have been involved with his work (I need to ask him). The Federal Advertising Agency, Inc. was not a government agency. I learned that from the oral history of Laura Elizabeth Seiler, a pioneer suffragist who was also a pioneer in advertising -- she retired (for the first time) in 1948 as a Vice-President of the Federal Advertising Agency, Inc.
I found this Time magazine blurb from 1927 that mentions it. The Federal Advertising Agency is also mentioned in this article from the Journal of Applied Psychology (1945). Also mentioned in Advertising the American Dream: Making Way for Modernity, 1920-1940.