The papers of Henry T. Ewald, co-founder (1911, with Frank Campbell) of Campbell-Ewald Company, Inc. a Detroit, Michigan Advertising Agency. Upon Campbell's retirement in 1917, Ewald became President and Chairman of the Board, serving as such until his death in 1953.

Under Ewald's leadership, the agency expanded, setting up branches in New York, Los Angeles, Chicago, Dallas and other cities, and had as clients such companies as General Motors, Burroughs Corporations, Detroit Edison, Great Lakes Steel and Firestone Tire and Rubber Company. Sample advertisements for General Motors and other auto companies are included in the papers, along with articles on the role of advertising during World War II, the V4 War Bond and Stamp Sales Campaign (1942), and articles on Campbell-Ewald and its 25th, 30th, 35th, 40th, 45th, and 50th anniversaries. An organizational chart (1942) is included.

A large part of the papers consists of articles and newspaper clippings on Ewald, including a biography eulogizing Ewald, and testimonial dinner addresses. A number of magazine and newspaper articles on advertising and the auto industry written by Ewald are also included. Two volumes on Campbell-Ewald are on the shelves and a large photo of the company's 40th anniversary and a number of large advertisements have been transferred to the map case.