The “Companies on Cards” file contains information on thousands of business firms arranged alphabetically on 3 × 5 cards. The data includes modern news clippings, notes culled from advertisements in various 19th and 20th century publications, and lists of participants and award winners at selected world's fairs. The files contain occasional clipped advertisements and color slides or negatives of company records, artifacts or artwork.

Historical data on business firms arranged alphabetically, containing names and addresses at the time the research was done, newspaper clippings, and some original advertising and other illustrations. Names of subsidiary companies are cross-indexed to the main company name. The series is contained in 22 file card boxes. The first box contains the code abbreviations and reference notes for the whole series.