The records consist of inbound correspondence received between the years 1911 and 1918. The correspondence is incomplete, with the bulk dating from 1915 to 1918. The records passed through the hands of a local antique dealer, who began to break them up and sell the pieces as thematic ephemera collections. For example, correspondence relating to firearms and sports fishing was sold separately.

The bulk of the correspondence consists of sales letters and invoices from manufacturers and wholesalers covering the wide range of semi-finished and manufactured goods sold by the Soo Hardware Company. A large number appear to be unsolicited mailings from salesmen, while others document a long working relationship. Many letters have trade catalogs, trade sheets, or price sheets attached. The majority of the letters have elaborate engraved letterheads that usually show a view of the vendor's factory and/or products. Many of the letters are exercises in salesmanship by regional sales agents, either pitched at selling the product to the Soo Hardware Company or making suggestions as to how to sell the product to retail customers, and illustrate the sales techniques of the time.

The records document a period of change for the hardware business, as an essentially nineteenth-century product mix was giving way to that of the inter-war years. The company still stocked horseshoes, harness, hoof pads, and manual farm equipment, but also electrical appliances, telephones, and auto parts. The records also show how World War I affected supply and demand. As a major border crossing and strategic transportation center, Sault Ste. Marie had several military installations and enjoyed a building boom during the war. However, companies dealing in materials like petroleum products and metals write of supply restrictions and embargoes with Canada. Companies also used patriotic images in their advertising.

The records also delineate the firm's trading network. Sault Ste. Marie is the site of the locks leading to Lake Superior, and the town was a center for both water and rail transportation. Not surprisingly, most of the vendors are located within the Great Lakes system, the surrounding areas of Wisconsin and Minnesota, and the Buffalo-New York City corridor that was then the principal link between the Great Lakes and the Atlantic. Chicago appears as the chief commercial focus, the location of banks, and the regional sales offices of large manufacturing firms. However, Ferguson maintained numerous ties with the New York City area and carried imported goods like Swedish iron and steel.

The records also describe an interesting mix of products and producers, including both large corporations like Standard Oil, Cambria Steel, Western Electric, Goodyear, and General Electric, and hundreds of small specialty firms. Familiar brand names like Sherwin-Williams and Glidden paints, Ever Ready batteries, Johnson Wax, Gillette razors, Goodyear tires, 3M sandpaper, Bissell, Regina, Hotpoint, Sterno, Crane, and Kohler jostle with products like Klaxon horns, Alcazar ranges, and Rat-Nip rat poison. The household products and appliances in particular are pitched at women or to husbands to get them to purchase "labor-saving" devices for their wives. The advertising for ranges, vacuum cleaners, and washing and ironing machines in particular contains contemporary images of domesticity and what constituted a well-run household. Also of note is the extensive use of asbestos before the associated health hazards were generally known.

The correspondence also includes some letters and orders from customers at a distance, including some of the steamship lines passing through Sault Ste. Marie. There are also letters from many banks, brokerage houses, insurance companies, trade journals, advertisers, and middlemen offering their services, and some information on the Ferguson family's investments.