New Jersey was a site of shipbuilding throughout the World War I period . Refineries and ammunition factories were also built to supply war material . Factories such as the Singer Company based in Elizabeth converted from making sewing machines to making weapon parts . Several camps and the forts were opened for soldiers during the war . The roles of these sites were generally to provide a location for soldiers to stock up on supplies , receive medical treatment , or become discharged . Several Allied ships were sunken off of the coast of New Jersey . Other factors contributing to the U.S. Entry into the war include German sabotage of both Black Tom in Jersey City , and the Kingsland Explosion in what is now Lyndhurst
Black Tom
Black Tom explosion
New Jersey in the 20th century