During the late 1890s new gun batteries were constructed at Fort Delaware. These batteries were part of a program initiated by the 1885 Board of Fortifications, a government board headed by Secretary of War William C. Endicott; the resulting system of fortifications is often called the Endicott program. Instead of many guns concentrated in a traditional thick-walled masonry structure, the Endicott batteries are spread out over a wide area, concealed behind concrete parapets flush with the surrounding terrain. As part of this program, Fort Delaware was supplemented by Fort DuPont on the river's west bank and Fort Mott on the east bank; these were the first forts of the Coast Defenses of the Delaware. Both of these were built new for the Endicott program, in both cases replacing earlier batteries. Part of an unfinished battery at Fort Mott from the 1870s was used for new batteries at that fort.