J. Walter Thompson Company. Frankfurt Office.

Founded in 1864, JWT is one of the largest and oldest advertising agencies in the United States. Harry Clark was an advertising executive who served as Director of JWT's Frankfurt Office and eventually of JWT's New York Office; Managing Director of Landsdowne Advertising, a JWT subsidiary; and co-founder of Smith Clark Associates, a consulting firm based in Princeton, N.J.

From the description of J. Walter Thompson Company Frankfurt Office Harry Clark papers, 1945-1992 and undated. (Duke University Library). WorldCat record id: 50145009