Constructed in 1856 to manufacture lead shot ammunition, the Shot Tower worked by pouring molten lead from the top through a series of sieves that formed the shot to proper size before it landed in a tank of cold water at the bottom. In the 1850s, lead from Dubuque was shipped to Saint Louis shotmakers who produced most of the lead shot in the Midwest, and George W. Rogers and Company built and operated the Dubuque Shot Tower in an effort to break that monopoly. The Saint Louis company then cut prices below production costs, ruining the Dubuque Shot Tower’s business after only three years. Local banker J.K. Graves bought all local shares at a low price in 1861, and with the Civil War underway he threatened to resume production there, but the Saint Louis company purchased the tower and abandoned it. Graves continued making shot for the Union Army by dropping lead down a deep mine shaft. The Shot Tower stood deserted from 1911 to 1959, when the Dubuque County Historical Society first restored the stone and brick structure. It is one of only a few remaining historic shot towers in the United States and the only one west of the Mississippi River.