In 1917, E.A. Stevenson & Company established the "Butter Works" on the site of the old Knox Hat factory. Stevenson started processing coconut and other vegetable oils and making margarine. Under later operation by E.F. Drew & Company, the Boonton plant grew to be one of the largest edible oils processors in the country. It was the largest industry in the town of Boonton during the 20th century. The plant closed in the early 1990s, and the site was developed for a Walmart store.