In the latter half of the 19th century, the town of Beekman experienced an industrial boom. Iron ore beds were discovered in the hamlets of Sylvan Lake, Beekman, and Clove Valley. Mining boomed until the 1890s, and many of the small ponds scattered about town today were originally open ore pits. The mining industry brought the railroad and a second influx of immigrants, mostly from Ireland. The arrival of these immigrant families created an entirely new culture in the town. In 1911, an 839-acre site in the hamlet of Green Haven was acquired by the state. Camp Whitman opened there in 1915 and was used for training soldiers in preparation for the invasion of Mexico and pursuit of Pancho Villa.