Named for the nitrocellulose used in smokeless powder, not nitroglycerin, the town of Nitro was built during World War I to manufacture munitions. DuPont Company, the premier explosives producer, had selected the Kanawha River site near Charleston but did not build the plant. Because of political objections to any company receiving such a large contract, on January 17, 1918, the War Department hired a New York engineering firm to build the plant using DuPont's preliminary plans, then engaged Hercules Powder to operate it under the supervision of Daniel J. Jackling, a copper executive.

Within 11 months, some 110,000 workers, using 104 railroad cars of materials daily, built not only a powder plant with nitric and sulfuric acid facilities, drying towers, storage, and proving grounds, but also a complete town with a civic center, hospital, and executive housing in the hills. The workers, who poured in from across the country to work on the project, included a young Clark Gable and future baseball great Pie Traynor. Rows and rows of prefabricated bungalows, up to 60 a day, were built and segregated by race and nationality. The town was constructed on the line between Putnam County and Kanawha County.

The war ended before Nitro was finished. With the Armistice, construction and initial production stopped, the companies and Jackling were released from their contracts, and the army inventoried and sold off the Nitro plant beginning August 1, 1919. The Charleston Industrial Corporation bought the facility and gradually attracted chemical-related industries and a stable population. As the Kanawha Valley chemical industry waned in the late 1900s, so did Nitro’s population, which was 6,618 in 2020, a decline of 18.0 percent from its peak of 8,074 in 1980.