This series consists of the historical materials relating to the various company histories that Marshall compiled throughout his career. Subseries A contains histories, ephemera, and photographs relating to the various companies. This group includes materials on all of the small, forgotten companies that were merged with or absorbed by the larger companies whose names survived through the years.

Subseries B, C, and D contain published sources of information on the various appliances and subjects of interest to Johnson. Subseries E are files on museum exhibitions and other museums Johnson visited and, in some cases, worked with. Subseries F contain the information Johnson compiled on various collectors and clubs for the appliances of interest. Subseries G are files and binders of photographs of the appliances and other items that Johnson had collected while researching particular products.

Subseries H are 65 ink on drafting linen production drawings (18"X24") for Wear-Ever's regular line of aluminum cookware products. These include drawings for coffee pots and perculators, tea kettles, pitchers, ricers, and several kinds of pans.

Subseries I are 203 ink on drafting linen production drawings for Wear-Ever's Kensington Ware line of aluminum giftware. While many of them were designed by Lurelle Guild, the drawings only note who drew them.

Subseries J are the actual small electric and hand-operated appliances, tools, and razors that Johnson collected to study while designing his products.