Hammill & Gillespie was established in 1848 by James P. Hammill (in what is now Manhattan’s historic South Street Seaport) as an importer of Bath Brick, a low-fired material from England, used for polishing metal. Joined in 1871 by Frederick R. Gillespie, the product line expanded to ceramics and other industrial applications. In this century, the business has steadily expanded to become a widely-admired supplier of clays and mineral products to American and international industry, with custom...