With creameries closing during the Great Depression, Missouri-born businessman JC Penney bought a Jacksonville, Florida creamery and named it after his prized Guernsey bull – Foremost. It originally operated in 12 southern communities and its net sales totaled $1 million the first year. By 1932, Penney had lost his personal fortune and was subject to unfounded charges that he had profited at the expense of fellow shareholders in the collapse of a Florida bank in which, he was a major investor. After a brief stay in a sanitarium, Penney returned to the post of chairman of the company and rebuilt his fortune.
Between 1932 and 1944, Foremost Dairies doubled the communities served and increased sales 10-fold. The company's major growth started in 1945 with the acquisition of Southwest Dairy Products Co. "It's better than good, it's Foremost" became a household slogan. During World War II, the U.S. military sparked Foremost's international growth and the creamery opened additional plants nationwide. Foremost Dairies became known as "the longest milk route in the world." Foremost Dairies was the third largest dairy company in the world by 1951. With the 1954 acquisition of Golden State Co. the largest dairy business in California - Foremost had operations in 23 states across the South and North as well as in Japan, the Philippines, Guam and Hawaii. Foremost established its headquarters in San Francisco, and it still lived by the golden rule established by Penney. Wherever it set up a facility, the organization wanted to teach local people how to operate it and then share in its success. In 1956, it made the key acquisition of Western Condensing Co. In Appleton, Wisconsin, that would eventually lead the Foremost name to Upper Midwest dairy producers. But troubled times hit in 1962, when the Federal Trade Commission said that Foremost's "dominant presence" could affect competition. The company was ordered to release ownership of its 10 most recent acquisitions. Foremost also sold all of its milk and ice cream plants east of the Mississippi River. In 1967, Foremost and McKesson merged. At the time, Foremost-McKesson included chemical, liquor and pharmaceutical companies as well as Foremost Foods Co. It also included the Wisconsin whey processing plants formerly operated under Western Condensing.