Galena, Illinois for mayor and aldermen on May 24, 1841, replacing the board of trustees; Charles S. Hempstead was elected the first mayor with 185 of the 356 votes cast. The first census was also held that year, finding 1,900 inhabitants. By 1845 Galena was producing nearly 27,000 tons of lead ore and Jo Daviess County was producing 80 percent of the lead in the United States. Once one of the most important cities in the state, Galena was a hub on the Mississippi River between St. Louis and St. Paul. Due to erosion, the Galena River is now inaccessible to steamboats.
Ore genesis classified hydrothermal deposits as "hypothermal", "mesothermal", "epithermal", and "telethermal". Epithermal deposits are hydrothermal ore deposits formed at low temperatures (50-200 °C) near the Earth´s surface (<1500 m), that fill veins, breccias, and stockworks. The age of formation of epithermal deposits in México is currently being investigated. "As they require the conjunction of specific environmental conditions to form, particular mineral deposit types tend to occupy specific geodynamic niches," therefore, this page has been organised by metal commodity. It is also possible to organise theories the other way, namely according to geological criteria of formation. Often ores of the same metal can