This paper will review the process employed by the fledgling DuPont Company in gunpowder manufacture on the banks of the Brandywine. Although this process predated formal recognition of the disciplines of chemical engineering or particle technology, it contains clear examples of unit operations to which these disciplines later brought systematic understanding and demonstrates the state of particle production in the early 19th century. The influence of both chemical and physical manipulations on the powder's burning reaction will be discussed.