and Borden. Post National acquisition of Kraft-Phenix At the time of the acquisition in 1930, National Dairy had sales of $315m compared with $85m for Kraft Phenix. National Dairy management ran the combined business. Following the Kraft-Phenix acquisition, the firm continued to be called National Dairy until 1969 when it changed its name to Kraftco. Historically, all of the firm's sales came from dairy products. However, the firm's product lines began to diversify away from dairy products to caramel candies, macaroni and cheese dinners and margarines. From the 1950s onward, the firm began to move away from low value added commodity dairy products, such as fluid milk. This trend would continue for the firm, through neglect and divestiture, until the primary remaining dairy product produced by the firm would be cheese. As a result, the modern history of the firm emphasizes the cheese history. In 1933, the company began marketing by radio sponsorship. In 1935, the Sealtest brand of ice cream was launched as a unified national brand to replace the firm's numerous regional brands. During World War II, the company sent four million pounds of cheese to Britain weekly. Product development and advertising helped the company to grow during the postwar years, launching sliced process cheese and Cheez Whiz, a brand of process cheese sauce, in the 1950s. During these years, Thomas McInnerney, National Dairy's founder, and James L. Kraft, Kraft's founder, died, and at the end of the decade, the divisions became less autonomous and even diversified to the glass-packaging business with the acquisition of Metro Glass in 1956. In 1947, the company tested the marketing power of the emerging medium of television by producing an hour-long drama/anthology series, the Kraft Television Theatre. The product advertised on the program, MacLaren's Imperial Cheese, was selected because "... [it had] not only had no advertising appropriation whatsoever, but had not even been distributed for several years." As described by internal documents of J. Walter Thompson—the advertising firm which conceived of the marketing test—the result was "although there was no other advertising support for it whatsoever, still grocery stores could not keep up with the demand." In the 1960s, product development became intense, launching fruit jellies, fruit preserves, marshmallows, barbecue sauces and Kraft Singles, a brand of individually wrapped cheese slices. During this decade, the company also expanded in many markets worldwide. In 1961, the firm acquired Dominion Dairies of Canada,